diff --git a/src/data/battler-tags.ts b/src/data/battler-tags.ts
index 65af0fb6ee8..579d068e882 100644
--- a/src/data/battler-tags.ts
+++ b/src/data/battler-tags.ts
@@ -2311,6 +2311,11 @@ export class AutotomizedTag extends BattlerTag {
   }
 }
 
+/**
+ * Tag implementing the {@link https://bulbapedia.bulbagarden.net/wiki/Substitute_(doll)#Effect | Substitute Doll} effect,
+ * for use with the moves Substitute and Shed Tail. Pokemon with this tag deflect most forms of received attack damage
+ * onto the tag. This tag also grants immunity to most Status moves and several move effects.
+ */
 export class SubstituteTag extends BattlerTag {
   /** The substitute's remaining HP. If HP is depleted, the Substitute fades. */
   public hp: number;
@@ -2330,7 +2335,11 @@ export class SubstituteTag extends BattlerTag {
 
     // Queue battle animation and message
     pokemon.scene.triggerPokemonBattleAnim(pokemon, PokemonAnimType.SUBSTITUTE_ADD);
-    pokemon.scene.queueMessage(i18next.t("battlerTags:substituteOnAdd", { pokemonNameWithAffix: getPokemonNameWithAffix(pokemon) }), 1500);
+    if (this.sourceMove === Moves.SHED_TAIL) {
+      pokemon.scene.queueMessage(i18next.t("battlerTags:shedTailOnAdd", { pokemonNameWithAffix: getPokemonNameWithAffix(pokemon) }), 1500);
+    } else {
+      pokemon.scene.queueMessage(i18next.t("battlerTags:substituteOnAdd", { pokemonNameWithAffix: getPokemonNameWithAffix(pokemon) }), 1500);
+    }
 
     // Remove any binding effects from the user
     pokemon.findAndRemoveTags(tag => tag instanceof DamagingTrapTag);
diff --git a/src/data/move.ts b/src/data/move.ts
index 27c27696650..71d97e4fb5c 100644
--- a/src/data/move.ts
+++ b/src/data/move.ts
@@ -37,6 +37,7 @@ import { SwitchSummonPhase } from "#app/phases/switch-summon-phase";
 import { SpeciesFormChangeRevertWeatherFormTrigger } from "./pokemon-forms";
 import { GameMode } from "#app/game-mode";
 import { applyChallenges, ChallengeType } from "./challenge";
+import { SwitchType } from "#enums/switch-type";
 
 export enum MoveCategory {
   PHYSICAL,
@@ -1476,8 +1477,13 @@ export class HalfSacrificialAttr extends MoveEffectAttr {
  * @see {@linkcode apply}
  */
 export class AddSubstituteAttr extends MoveEffectAttr {
-  constructor() {
+  /** The ratio of the user's max HP that is required to apply this effect */
+  private hpCost: number;
+
+  constructor(hpCost: number = 0.25) {
     super(true);
+
+    this.hpCost = hpCost;
   }
 
   /**
@@ -1493,8 +1499,7 @@ export class AddSubstituteAttr extends MoveEffectAttr {
       return false;
     }
 
-    const hpCost = Math.floor(user.getMaxHp() / 4);
-    user.damageAndUpdate(hpCost, HitResult.OTHER, false, true, true);
+    user.damageAndUpdate(Math.floor(user.getMaxHp() * this.hpCost), HitResult.OTHER, false, true, true);
     user.addTag(BattlerTagType.SUBSTITUTE, 0, move.id, user.id);
     return true;
   }
@@ -1507,7 +1512,7 @@ export class AddSubstituteAttr extends MoveEffectAttr {
   }
 
   getCondition(): MoveConditionFunc {
-    return (user, target, move) => !user.getTag(SubstituteTag) && user.hp > Math.floor(user.getMaxHp() / 4) && user.getMaxHp() > 1;
+    return (user, target, move) => !user.getTag(SubstituteTag) && user.hp > Math.floor(user.getMaxHp() * this.hpCost) && user.getMaxHp() > 1;
   }
 
   getFailedText(user: Pokemon, target: Pokemon, move: Move, cancelled: Utils.BooleanHolder): string | null {
@@ -5151,9 +5156,9 @@ export class RevivalBlessingAttr extends MoveEffectAttr {
         if (user.scene.currentBattle.double && user.scene.getEnemyParty().length > 1) {
           const allyPokemon = user.getAlly();
           if (slotIndex<=1) {
-            user.scene.unshiftPhase(new SwitchSummonPhase(user.scene, pokemon.getFieldIndex(), slotIndex, false, false, false));
+            user.scene.unshiftPhase(new SwitchSummonPhase(user.scene, SwitchType.SWITCH, pokemon.getFieldIndex(), slotIndex, false, false));
           } else if (allyPokemon.isFainted()) {
-            user.scene.unshiftPhase(new SwitchSummonPhase(user.scene, allyPokemon.getFieldIndex(), slotIndex, false, false, false));
+            user.scene.unshiftPhase(new SwitchSummonPhase(user.scene, SwitchType.SWITCH, allyPokemon.getFieldIndex(), slotIndex, false, false));
           }
         }
         resolve(true);
@@ -5176,72 +5181,69 @@ export class RevivalBlessingAttr extends MoveEffectAttr {
 export class ForceSwitchOutAttr extends MoveEffectAttr {
   constructor(
     private selfSwitch: boolean = false,
-    private batonPass: boolean = false
+    private switchType: SwitchType = SwitchType.SWITCH
   ) {
     super(false, MoveEffectTrigger.POST_APPLY, false, true);
   }
 
   isBatonPass() {
-    return this.batonPass;
+    return this.switchType === SwitchType.BATON_PASS;
   }
 
-  // TODO: Why is this a Promise?
-  apply(user: Pokemon, target: Pokemon, move: Move, args: any[]): Promise<boolean> {
-    return new Promise(resolve => {
+  apply(user: Pokemon, target: Pokemon, move: Move, args: any[]): boolean {
+    // Check if the move category is not STATUS or if the switch out condition is not met
+    if (!this.getSwitchOutCondition()(user, target, move)) {
+      return false;
+    }
 
-      if (!this.getSwitchOutCondition()(user, target, move)) {
-        return resolve(false);
+    /**
+     * Move the switch out logic inside the conditional block
+     * This ensures that the switch out only happens when the conditions are met
+     */
+    const switchOutTarget = this.selfSwitch ? user : target;
+    if (switchOutTarget instanceof PlayerPokemon) {
+      switchOutTarget.leaveField(this.switchType === SwitchType.SWITCH);
+
+      if (switchOutTarget.hp > 0) {
+        user.scene.prependToPhase(new SwitchPhase(user.scene, this.switchType, switchOutTarget.getFieldIndex(), true, true), MoveEndPhase);
+        return true;
+      }
+      return false;
+    } else if (user.scene.currentBattle.battleType !== BattleType.WILD) {
+      // Switch out logic for trainer battles
+      switchOutTarget.leaveField(this.switchType === SwitchType.SWITCH);
+
+      if (switchOutTarget.hp > 0) {
+        // for opponent switching out
+        user.scene.prependToPhase(new SwitchSummonPhase(user.scene, this.switchType, switchOutTarget.getFieldIndex(),
+          (user.scene.currentBattle.trainer ? user.scene.currentBattle.trainer.getNextSummonIndex((switchOutTarget as EnemyPokemon).trainerSlot) : 0),
+          false, false), MoveEndPhase);
+      }
+    } else {
+      // Switch out logic for everything else (eg: WILD battles)
+      switchOutTarget.leaveField(false);
+
+      if (switchOutTarget.hp) {
+        user.scene.queueMessage(i18next.t("moveTriggers:fled", {pokemonName: getPokemonNameWithAffix(switchOutTarget)}), null, true, 500);
+
+        // in double battles redirect potential moves off fled pokemon
+        if (switchOutTarget.scene.currentBattle.double) {
+          const allyPokemon = switchOutTarget.getAlly();
+          switchOutTarget.scene.redirectPokemonMoves(switchOutTarget, allyPokemon);
+        }
       }
 
-      // Move the switch out logic inside the conditional block
-      // This ensures that the switch out only happens when the conditions are met
-      const switchOutTarget = this.selfSwitch ? user : target;
-      if (switchOutTarget instanceof PlayerPokemon) {
-        switchOutTarget.leaveField(!this.batonPass);
-
-        if (switchOutTarget.hp > 0) {
-          user.scene.prependToPhase(new SwitchPhase(user.scene, switchOutTarget.getFieldIndex(), true, true), MoveEndPhase);
-          resolve(true);
-        } else {
-          resolve(false);
-        }
-        return;
-      } else if (user.scene.currentBattle.battleType !== BattleType.WILD) {
-        // Switch out logic for trainer battles
-        switchOutTarget.leaveField(!this.batonPass);
-
-        if (switchOutTarget.hp > 0) {
-          // for opponent switching out
-          user.scene.prependToPhase(new SwitchSummonPhase(user.scene, switchOutTarget.getFieldIndex(),
-            (user.scene.currentBattle.trainer ? user.scene.currentBattle.trainer.getNextSummonIndex((switchOutTarget as EnemyPokemon).trainerSlot) : 0),
-            false, this.batonPass, false), MoveEndPhase);
-        }
-      } else {
-        // Switch out logic for everything else (eg: WILD battles)
-        switchOutTarget.leaveField(false);
+      if (!switchOutTarget.getAlly()?.isActive(true)) {
+        user.scene.clearEnemyHeldItemModifiers();
 
         if (switchOutTarget.hp) {
-          user.scene.queueMessage(i18next.t("moveTriggers:fled", {pokemonName: getPokemonNameWithAffix(switchOutTarget)}), null, true, 500);
-
-          // in double battles redirect potential moves off fled pokemon
-          if (switchOutTarget.scene.currentBattle.double) {
-            const allyPokemon = switchOutTarget.getAlly();
-            switchOutTarget.scene.redirectPokemonMoves(switchOutTarget, allyPokemon);
-          }
-        }
-
-        if (!switchOutTarget.getAlly()?.isActive(true)) {
-          user.scene.clearEnemyHeldItemModifiers();
-
-          if (switchOutTarget.hp) {
-            user.scene.pushPhase(new BattleEndPhase(user.scene));
-            user.scene.pushPhase(new NewBattlePhase(user.scene));
-          }
+          user.scene.pushPhase(new BattleEndPhase(user.scene));
+          user.scene.pushPhase(new NewBattlePhase(user.scene));
         }
       }
+    }
 
-      resolve(true);
-    });
+	  return true;
   }
 
   getCondition(): MoveConditionFunc {
@@ -5270,7 +5272,7 @@ export class ForceSwitchOutAttr extends MoveEffectAttr {
       }
 
       if (!player && user.scene.currentBattle.battleType === BattleType.WILD) {
-        if (this.batonPass) {
+        if (this.isBatonPass()) {
           return false;
         }
         // Don't allow wild opponents to flee on the boss stage since it can ruin a run early on
@@ -5291,7 +5293,7 @@ export class ForceSwitchOutAttr extends MoveEffectAttr {
       return -20;
     }
     let ret = this.selfSwitch ? Math.floor((1 - user.getHpRatio()) * 20) : super.getUserBenefitScore(user, target, move);
-    if (this.selfSwitch && this.batonPass) {
+    if (this.selfSwitch && this.isBatonPass()) {
       const statStageTotal = user.getStatStages().reduce((s: integer, total: integer) => total += s, 0);
       ret = ret / 2 + (Phaser.Tweens.Builders.GetEaseFunction("Sine.easeOut")(Math.min(Math.abs(statStageTotal), 10) / 10) * (statStageTotal >= 0 ? 10 : -10));
     }
@@ -5301,10 +5303,7 @@ export class ForceSwitchOutAttr extends MoveEffectAttr {
 
 
 export class ChillyReceptionAttr extends ForceSwitchOutAttr {
-
-  // using inherited constructor
-
-  apply(user: Pokemon, target: Pokemon, move: Move, args: any[]): Promise<boolean> {
+  apply(user: Pokemon, target: Pokemon, move: Move, args: any[]): boolean {
     user.scene.arena.trySetWeather(WeatherType.SNOW, true);
     return super.apply(user, target, move, args);
   }
@@ -7394,7 +7393,7 @@ export function initMoves() {
     new AttackMove(Moves.DRAGON_BREATH, Type.DRAGON, MoveCategory.SPECIAL, 60, 100, 20, 30, 0, 2)
       .attr(StatusEffectAttr, StatusEffect.PARALYSIS),
     new SelfStatusMove(Moves.BATON_PASS, Type.NORMAL, -1, 40, -1, 0, 2)
-      .attr(ForceSwitchOutAttr, true, true)
+      .attr(ForceSwitchOutAttr, true, SwitchType.BATON_PASS)
       .hidesUser(),
     new StatusMove(Moves.ENCORE, Type.NORMAL, 100, 5, -1, 0, 2)
       .attr(AddBattlerTagAttr, BattlerTagType.ENCORE, false, true)
@@ -7820,7 +7819,7 @@ export function initMoves() {
       .makesContact(false)
       .target(MoveTarget.ATTACKER),
     new AttackMove(Moves.U_TURN, Type.BUG, MoveCategory.PHYSICAL, 70, 100, 20, -1, 0, 4)
-      .attr(ForceSwitchOutAttr, true, false),
+      .attr(ForceSwitchOutAttr, true),
     new AttackMove(Moves.CLOSE_COMBAT, Type.FIGHTING, MoveCategory.PHYSICAL, 120, 100, 5, -1, 0, 4)
       .attr(StatStageChangeAttr, [ Stat.DEF, Stat.SPDEF ], -1, true),
     new AttackMove(Moves.PAYBACK, Type.DARK, MoveCategory.PHYSICAL, 50, 100, 10, -1, 0, 4)
@@ -8253,7 +8252,7 @@ export function initMoves() {
     new AttackMove(Moves.GRASS_PLEDGE, Type.GRASS, MoveCategory.SPECIAL, 80, 100, 10, -1, 0, 5)
       .partial(),
     new AttackMove(Moves.VOLT_SWITCH, Type.ELECTRIC, MoveCategory.SPECIAL, 70, 100, 20, -1, 0, 5)
-      .attr(ForceSwitchOutAttr, true, false),
+      .attr(ForceSwitchOutAttr, true),
     new AttackMove(Moves.STRUGGLE_BUG, Type.BUG, MoveCategory.SPECIAL, 50, 100, 20, 100, 0, 5)
       .attr(StatStageChangeAttr, [ Stat.SPATK ], -1)
       .target(MoveTarget.ALL_NEAR_ENEMIES),
@@ -8421,7 +8420,7 @@ export function initMoves() {
       .target(MoveTarget.ALL_NEAR_ENEMIES),
     new StatusMove(Moves.PARTING_SHOT, Type.DARK, 100, 20, -1, 0, 6)
       .attr(StatStageChangeAttr, [ Stat.ATK, Stat.SPATK ], -1, false, null, true, true, MoveEffectTrigger.PRE_APPLY)
-      .attr(ForceSwitchOutAttr, true, false)
+      .attr(ForceSwitchOutAttr, true)
       .soundBased(),
     new StatusMove(Moves.TOPSY_TURVY, Type.DARK, -1, 20, -1, 0, 6)
       .attr(InvertStatsAttr),
@@ -9176,7 +9175,7 @@ export function initMoves() {
       .attr(StatStageChangeAttr, [ Stat.ATK, Stat.DEF ], 1)
       .target(MoveTarget.NEAR_ALLY),
     new AttackMove(Moves.FLIP_TURN, Type.WATER, MoveCategory.PHYSICAL, 60, 100, 20, -1, 0, 8)
-      .attr(ForceSwitchOutAttr, true, false),
+      .attr(ForceSwitchOutAttr, true),
     new AttackMove(Moves.TRIPLE_AXEL, Type.ICE, MoveCategory.PHYSICAL, 20, 90, 10, -1, 0, 8)
       .attr(MultiHitAttr, MultiHitType._3)
       .attr(MultiHitPowerIncrementAttr, 3)
@@ -9503,10 +9502,11 @@ export function initMoves() {
       .attr(MovePowerMultiplierAttr, (user, target, move) => target.getAttackTypeEffectiveness(move.type, user) >= 2 ? 5461/4096 : 1)
       .makesContact(),
     new SelfStatusMove(Moves.SHED_TAIL, Type.NORMAL, -1, 10, -1, 0, 9)
-      .unimplemented(),
+      .attr(AddSubstituteAttr, 0.5)
+      .attr(ForceSwitchOutAttr, true, SwitchType.SHED_TAIL),
     new SelfStatusMove(Moves.CHILLY_RECEPTION, Type.ICE, -1, 10, -1, 0, 9)
       .attr(PreMoveMessageAttr, (user, move) => i18next.t("moveTriggers:chillyReception", {pokemonName: getPokemonNameWithAffix(user)}))
-      .attr(ChillyReceptionAttr, true, false),
+      .attr(ChillyReceptionAttr, true),
     new SelfStatusMove(Moves.TIDY_UP, Type.NORMAL, -1, 10, -1, 0, 9)
       .attr(StatStageChangeAttr, [ Stat.ATK, Stat.SPD ], 1, true, null, true, true)
       .attr(RemoveArenaTrapAttr, true)
diff --git a/src/enums/switch-type.ts b/src/enums/switch-type.ts
new file mode 100644
index 00000000000..b25ba6ad119
--- /dev/null
+++ b/src/enums/switch-type.ts
@@ -0,0 +1,12 @@
+/**
+ * Indicates the type of switch functionality that a {@linkcode SwitchPhase}
+ * or {@linkcode SwitchSummonPhase} will carry out.
+ */
+export enum SwitchType {
+  /** Basic switchout where the Pokemon to switch in is selected */
+  SWITCH,
+  /** Transfers stat stages and other effects from the returning Pokemon to the switched in Pokemon */
+  BATON_PASS,
+  /** Transfers the returning Pokemon's Substitute to the switched in Pokemon */
+  SHED_TAIL
+}
diff --git a/src/field/pokemon.ts b/src/field/pokemon.ts
index 14f93809414..21deb3790e1 100644
--- a/src/field/pokemon.ts
+++ b/src/field/pokemon.ts
@@ -61,6 +61,7 @@ import { Challenges } from "#enums/challenges";
 import { PokemonAnimType } from "#app/enums/pokemon-anim-type";
 import { PLAYER_PARTY_MAX_SIZE } from "#app/constants";
 import { MysteryEncounterPokemonData } from "#app/data/mystery-encounters/mystery-encounter-pokemon-data";
+import { SwitchType } from "#enums/switch-type";
 
 export enum FieldPosition {
   CENTER,
@@ -4003,16 +4004,17 @@ export class PlayerPokemon extends Pokemon {
   /**
    * Causes this mon to leave the field (via {@linkcode leaveField}) and then
    * opens the party switcher UI to switch a new mon in
-   * @param batonPass Indicates if this switch was caused by a baton pass (and
-   * thus should maintain active mon effects)
+   * @param switchType the {@linkcode SwitchType} for this switch-out. If this is
+   * `BATON_PASS` or `SHED_TAIL`, this Pokemon's effects are not cleared upon leaving
+   * the field.
    */
-  switchOut(batonPass: boolean): Promise<void> {
+  switchOut(switchType: SwitchType = SwitchType.SWITCH): Promise<void> {
     return new Promise(resolve => {
-      this.leaveField(!batonPass);
+      this.leaveField(switchType === SwitchType.SWITCH);
 
       this.scene.ui.setMode(Mode.PARTY, PartyUiMode.FAINT_SWITCH, this.getFieldIndex(), (slotIndex: integer, option: PartyOption) => {
         if (slotIndex >= this.scene.currentBattle.getBattlerCount() && slotIndex < 6) {
-          this.scene.prependToPhase(new SwitchSummonPhase(this.scene, this.getFieldIndex(), slotIndex, false, batonPass), MoveEndPhase);
+          this.scene.prependToPhase(new SwitchSummonPhase(this.scene, switchType, this.getFieldIndex(), slotIndex, false), MoveEndPhase);
         }
         this.scene.ui.setMode(Mode.MESSAGE).then(resolve);
       }, PartyUiHandler.FilterNonFainted);
@@ -4074,11 +4076,11 @@ export class PlayerPokemon extends Pokemon {
             const allyPokemon = this.getAlly();
             if (slotIndex<=1) {
               // Revived ally pokemon
-              this.scene.unshiftPhase(new SwitchSummonPhase(this.scene, pokemon.getFieldIndex(), slotIndex, false, false, true));
+              this.scene.unshiftPhase(new SwitchSummonPhase(this.scene, SwitchType.SWITCH, pokemon.getFieldIndex(), slotIndex, false, true));
               this.scene.unshiftPhase(new ToggleDoublePositionPhase(this.scene, true));
             } else if (allyPokemon.isFainted()) {
               // Revived party pokemon, and ally pokemon is fainted
-              this.scene.unshiftPhase(new SwitchSummonPhase(this.scene, allyPokemon.getFieldIndex(), slotIndex, false, false, true));
+              this.scene.unshiftPhase(new SwitchSummonPhase(this.scene, SwitchType.SWITCH, allyPokemon.getFieldIndex(), slotIndex, false, true));
               this.scene.unshiftPhase(new ToggleDoublePositionPhase(this.scene, true));
             }
           }
diff --git a/src/locales/de/battler-tags.json b/src/locales/de/battler-tags.json
index 2f8a8d0c438..6cc0e93ffb2 100644
--- a/src/locales/de/battler-tags.json
+++ b/src/locales/de/battler-tags.json
@@ -71,6 +71,7 @@
   "disabledOnAdd": " {{moveName}} von {{pokemonNameWithAffix}} wurde blockiert!",
   "disabledLapse": "{{moveName}} von {{pokemonNameWithAffix}} ist nicht länger blockiert!",
   "tarShotOnAdd": "{{pokemonNameWithAffix}} ist nun schwach gegenüber Feuer-Attacken!",
+  "shedTailOnAdd": "{{pokemonNameWithAffix}} wirft seinen Schwanz ab, um eine Ablenkung zu schaffen!",
   "substituteOnAdd": "Ein Delegator von {{pokemonNameWithAffix}} ist erschienen!",
   "substituteOnHit": "Der Delegator steckt den Schlag für {{pokemonNameWithAffix}} ein!",
   "substituteOnRemove": "Der Delegator von {{pokemonNameWithAffix}} hört auf zu wirken!"
diff --git a/src/locales/en/battler-tags.json b/src/locales/en/battler-tags.json
index 6a5eeee2577..520ac2a6202 100644
--- a/src/locales/en/battler-tags.json
+++ b/src/locales/en/battler-tags.json
@@ -71,6 +71,7 @@
   "disabledOnAdd": "{{pokemonNameWithAffix}}'s {{moveName}}\nwas disabled!",
   "disabledLapse": "{{pokemonNameWithAffix}}'s {{moveName}}\nis no longer disabled.",
   "tarShotOnAdd": "{{pokemonNameWithAffix}} became weaker to fire!",
+  "shedTailOnAdd": "{{pokemonNameWithAffix}} shed its tail to create a decoy!",
   "substituteOnAdd": "{{pokemonNameWithAffix}} put in a substitute!",
   "substituteOnHit": "The substitute took damage for {{pokemonNameWithAffix}}!",
   "substituteOnRemove": "{{pokemonNameWithAffix}}'s substitute faded!",
diff --git a/src/locales/es/battler-tags.json b/src/locales/es/battler-tags.json
index bb4f0fe6c8a..b4d26f590c3 100644
--- a/src/locales/es/battler-tags.json
+++ b/src/locales/es/battler-tags.json
@@ -71,6 +71,7 @@
   "disabledOnAdd": "¡Se ha anulado el movimiento {{moveName}}\nde {{pokemonNameWithAffix}}!",
   "disabledLapse": "¡El movimiento {{moveName}} de {{pokemonNameWithAffix}} ya no está anulado!",
   "tarShotOnAdd": "¡{{pokemonNameWithAffix}} se ha vuelto débil ante el fuego!",
+  "shedTailOnAdd": "{{pokemonNameWithAffix}} se desprende\nde un segmento de su cuerpo y lo usa comoseñuelo!",
   "substituteOnAdd": "¡{{pokemonNameWithAffix}} creó un sustituto!",
   "substituteOnHit": "¡El sustituto recibe daño en lugar del {{pokemonNameWithAffix}}!",
   "substituteOnRemove": "¡El sustituto del {{pokemonNameWithAffix}} se debilitó!"
diff --git a/src/locales/fr/battler-tags.json b/src/locales/fr/battler-tags.json
index 93b70490ed6..b52f688320e 100644
--- a/src/locales/fr/battler-tags.json
+++ b/src/locales/fr/battler-tags.json
@@ -71,6 +71,7 @@
   "disabledOnAdd": "La capacité {{moveName}}\nde {{pokemonNameWithAffix}} est mise sous entrave !",
   "disabledLapse": "La capacité {{moveName}}\nde {{pokemonNameWithAffix}} n’est plus sous entrave !",
   "tarShotOnAdd": "{{pokemonNameWithAffix}} est maintenant\nvulnérable au feu !",
+  "shedTailOnAdd": "{{pokemonNameWithAffix}} détache\nsa queue pour créer un leurre !",
   "substituteOnAdd": "{{pokemonNameWithAffix}}\ncrée un clone !",
   "substituteOnHit": "Le clone subit les dégâts à la place\nde {{pokemonNameWithAffix}} !",
   "substituteOnRemove": "Le clone de {{pokemonNameWithAffix}}\ndisparait…"
diff --git a/src/locales/it/battler-tags.json b/src/locales/it/battler-tags.json
index 6ab69f4efa2..a7062c46677 100644
--- a/src/locales/it/battler-tags.json
+++ b/src/locales/it/battler-tags.json
@@ -71,6 +71,7 @@
   "disabledOnAdd": "La mossa {{moveName}} di\n{{pokemonNameWithAffix}} è stata bloccata!",
   "disabledLapse": "La mossa {{moveName}} di\n{{pokemonNameWithAffix}} non è più bloccata!",
   "tarShotOnAdd": "{{pokemonNameWithAffix}} è diventato vulnerabile\nal tipo Fuoco!",
+  "shedTailOnAdd": "{{pokemonNameWithAffix}} si taglia\nla coda e ne fa un sostituto!",
   "substituteOnAdd": "Appare un sostituto di {{pokemonNameWithAffix}}!",
   "substituteOnHit": "Il sostituto viene colpito al posto di {{pokemonNameWithAffix}}!",
   "substituteOnRemove": "Il sostituto di {{pokemonNameWithAffix}} svanisce!"
diff --git a/src/locales/ja/battler-tags.json b/src/locales/ja/battler-tags.json
index f8c6d44c0b4..fef8def1328 100644
--- a/src/locales/ja/battler-tags.json
+++ b/src/locales/ja/battler-tags.json
@@ -70,5 +70,6 @@
   "stockpilingOnAdd": "{{pokemonNameWithAffix}}は　{{stockpiledCount}}つ　たくわえた!",
   "disabledOnAdd": "{{pokemonNameWithAffix}}の\n{{moveName}}\nを　封じこめた！",
   "disabledLapse": "{{pokemonNameWithAffix}}の\nかなしばりが　解けた！",
-  "tarShotOnAdd": "{{pokemonNameWithAffix}}は　ほのおに　弱くなった！"
+  "tarShotOnAdd": "{{pokemonNameWithAffix}}は　ほのおに　弱くなった！",
+  "shedTailOnAdd": "{{pokemonNameWithAffix}}は\nしっぽを　切って　みがわりにした！"
 }
diff --git a/src/locales/ko/battler-tags.json b/src/locales/ko/battler-tags.json
index 1cd6c86377e..53fab7d10ba 100644
--- a/src/locales/ko/battler-tags.json
+++ b/src/locales/ko/battler-tags.json
@@ -71,6 +71,7 @@
   "disabledOnAdd": "{{pokemonNameWithAffix}}의 {{moveName}}[[는]]\n사용할 수 없다!",
   "disabledLapse": "{{pokemonNameWithAffix}}의 {{moveName}}[[는]]\n이제 사용할 수 있다.",
   "tarShotOnAdd": "{{pokemonNameWithAffix}}[[는]] 불꽃에 약해졌다!",
+  "shedTailOnAdd": "{{pokemonNameWithAffix}}[[는]] 꼬리를 잘라 대타로 삼았다!",
   "substituteOnAdd": "{{pokemonNameWithAffix}}의\n대타가 나타났다!",
   "substituteOnHit": "{{pokemonNameWithAffix}}[[를]] 대신하여\n대타가 공격을 받았다!",
   "substituteOnRemove": "{{pokemonNameWithAffix}}의\n대타는 사라져 버렸다..."
diff --git a/src/locales/zh_CN/battler-tags.json b/src/locales/zh_CN/battler-tags.json
index a7859380b7a..565fa8e754e 100644
--- a/src/locales/zh_CN/battler-tags.json
+++ b/src/locales/zh_CN/battler-tags.json
@@ -71,6 +71,7 @@
   "disabledOnAdd": "封住了{{pokemonNameWithAffix}}的\n{{moveName}}！",
   "disabledLapse": "{{pokemonNameWithAffix}}的\n定身法解除了！",
   "tarShotOnAdd": "{{pokemonNameWithAffix}}\n变得怕火了！",
+  "shedTailOnAdd": "{{pokemonNameWithAffix}}\n断掉尾巴并将其作为替身了！",
   "substituteOnAdd": "{{pokemonNameWithAffix}}的\n替身出现了！",
   "substituteOnHit": "替身代替{{pokemonNameWithAffix}}\n承受了攻击！",
   "substituteOnRemove": "{{pokemonNameWithAffix}}的\n替身消失了……"
diff --git a/src/locales/zh_TW/battler-tags.json b/src/locales/zh_TW/battler-tags.json
index 49b19f5efdc..d6cb5d0aa43 100644
--- a/src/locales/zh_TW/battler-tags.json
+++ b/src/locales/zh_TW/battler-tags.json
@@ -71,6 +71,7 @@
   "disabledOnAdd": "封住了{{pokemonNameWithAffix}}的\n{moveName}}！",
   "disabledLapse": "{{pokemonNameWithAffix}}的\n定身法解除了！",
   "tarShotOnAdd": "{{pokemonNameWithAffix}}\n變得怕火了！",
+  "shedTailOnAdd": "{{pokemonNameWithAffix}}\n截斷尾巴，把它做成了替身！",
   "substituteOnAdd": "{{pokemonNameWithAffix}}的\n替身出現了！",
   "substituteOnHit": "替身代替{{pokemonNameWithAffix}}承受了攻擊！",
   "substituteOnRemove": "{{pokemonNameWithAffix}}的\n替身消失了……"
diff --git a/src/phases/check-switch-phase.ts b/src/phases/check-switch-phase.ts
index a069ba224a2..8849d304435 100644
--- a/src/phases/check-switch-phase.ts
+++ b/src/phases/check-switch-phase.ts
@@ -8,6 +8,7 @@ import { BattlePhase } from "./battle-phase";
 import { PostSummonPhase } from "./post-summon-phase";
 import { SummonMissingPhase } from "./summon-missing-phase";
 import { SwitchPhase } from "./switch-phase";
+import { SwitchType } from "#enums/switch-type";
 
 export class CheckSwitchPhase extends BattlePhase {
   protected fieldIndex: integer;
@@ -50,7 +51,7 @@ export class CheckSwitchPhase extends BattlePhase {
       this.scene.ui.setMode(Mode.CONFIRM, () => {
         this.scene.ui.setMode(Mode.MESSAGE);
         this.scene.tryRemovePhase(p => p instanceof PostSummonPhase && p.player && p.fieldIndex === this.fieldIndex);
-        this.scene.unshiftPhase(new SwitchPhase(this.scene, this.fieldIndex, false, true));
+        this.scene.unshiftPhase(new SwitchPhase(this.scene, SwitchType.SWITCH, this.fieldIndex, false, true));
         this.end();
       }, () => {
         this.scene.ui.setMode(Mode.MESSAGE);
diff --git a/src/phases/faint-phase.ts b/src/phases/faint-phase.ts
index 41384e5e491..ba25225f6e0 100644
--- a/src/phases/faint-phase.ts
+++ b/src/phases/faint-phase.ts
@@ -18,6 +18,7 @@ import { GameOverPhase } from "./game-over-phase";
 import { SwitchPhase } from "./switch-phase";
 import { VictoryPhase } from "./victory-phase";
 import { SpeciesFormChangeActiveTrigger } from "#app/data/pokemon-forms";
+import { SwitchType } from "#enums/switch-type";
 
 export class FaintPhase extends PokemonPhase {
   private preventEndure: boolean;
@@ -106,14 +107,14 @@ export class FaintPhase extends PokemonPhase {
          * If previous conditions weren't met, and the player has at least 1 legal Pokemon off the field,
          * push a phase that prompts the player to summon a Pokemon from their party.
          */
-        this.scene.pushPhase(new SwitchPhase(this.scene, this.fieldIndex, true, false));
+        this.scene.pushPhase(new SwitchPhase(this.scene, SwitchType.SWITCH, this.fieldIndex, true, false));
       }
     } else {
       this.scene.unshiftPhase(new VictoryPhase(this.scene, this.battlerIndex));
       if ([BattleType.TRAINER, BattleType.MYSTERY_ENCOUNTER].includes(this.scene.currentBattle.battleType)) {
         const hasReservePartyMember = !!this.scene.getEnemyParty().filter(p => p.isActive() && !p.isOnField() && p.trainerSlot === (pokemon as EnemyPokemon).trainerSlot).length;
         if (hasReservePartyMember) {
-          this.scene.pushPhase(new SwitchSummonPhase(this.scene, this.fieldIndex, -1, false, false, false));
+          this.scene.pushPhase(new SwitchSummonPhase(this.scene, SwitchType.SWITCH, this.fieldIndex, -1, false, false));
         }
       }
     }
diff --git a/src/phases/mystery-encounter-phases.ts b/src/phases/mystery-encounter-phases.ts
index 007b69650b9..60755095cca 100644
--- a/src/phases/mystery-encounter-phases.ts
+++ b/src/phases/mystery-encounter-phases.ts
@@ -24,6 +24,7 @@ import { NewBattlePhase } from "#app/phases/new-battle-phase";
 import { GameOverPhase } from "#app/phases/game-over-phase";
 import { SwitchPhase } from "#app/phases/switch-phase";
 import { SeenEncounterData } from "#app/data/mystery-encounters/mystery-encounter-save-data";
+import { SwitchType } from "#enums/switch-type";
 
 /**
  * Will handle (in order):
@@ -241,7 +242,7 @@ export class MysteryEncounterBattleStartCleanupPhase extends Phase {
     const playerField = this.scene.getPlayerField();
     playerField.forEach((pokemon, i) => {
       if (!pokemon.isAllowedInBattle() && legalPlayerPartyPokemon.length > i) {
-        this.scene.unshiftPhase(new SwitchPhase(this.scene, i, true, false));
+        this.scene.unshiftPhase(new SwitchPhase(this.scene, SwitchType.SWITCH, i, true, false));
       }
     });
 
diff --git a/src/phases/return-phase.ts b/src/phases/return-phase.ts
index 19c73816b36..eb587201585 100644
--- a/src/phases/return-phase.ts
+++ b/src/phases/return-phase.ts
@@ -1,10 +1,11 @@
 import BattleScene from "#app/battle-scene";
 import { SpeciesFormChangeActiveTrigger } from "#app/data/pokemon-forms";
+import { SwitchType } from "#enums/switch-type";
 import { SwitchSummonPhase } from "./switch-summon-phase";
 
 export class ReturnPhase extends SwitchSummonPhase {
   constructor(scene: BattleScene, fieldIndex: integer) {
-    super(scene, fieldIndex, -1, true, false);
+    super(scene, SwitchType.SWITCH, fieldIndex, -1, true);
   }
 
   switchAndSummon(): void {
diff --git a/src/phases/switch-phase.ts b/src/phases/switch-phase.ts
index b1a2e991ed8..f5ce2179715 100644
--- a/src/phases/switch-phase.ts
+++ b/src/phases/switch-phase.ts
@@ -1,4 +1,5 @@
 import BattleScene from "#app/battle-scene";
+import { SwitchType } from "#enums/switch-type";
 import PartyUiHandler, { PartyUiMode, PartyOption } from "#app/ui/party-ui-handler";
 import { Mode } from "#app/ui/ui";
 import { BattlePhase } from "./battle-phase";
@@ -9,22 +10,25 @@ import { SwitchSummonPhase } from "./switch-summon-phase";
  * for the player (if a switch would be valid for the current battle state).
  */
 export class SwitchPhase extends BattlePhase {
-  protected fieldIndex: integer;
-  private isModal: boolean;
-  private doReturn: boolean;
+  protected readonly fieldIndex: integer;
+  private readonly switchType: SwitchType;
+  private readonly isModal: boolean;
+  private readonly doReturn: boolean;
 
   /**
      * Creates a new SwitchPhase
      * @param scene {@linkcode BattleScene} Current battle scene
+     * @param switchType {@linkcode SwitchType} The type of switch logic this phase implements
      * @param fieldIndex Field index to switch out
      * @param isModal Indicates if the switch should be forced (true) or is
      * optional (false).
      * @param doReturn Indicates if the party member on the field should be
      * recalled to ball or has already left the field. Passed to {@linkcode SwitchSummonPhase}.
      */
-  constructor(scene: BattleScene, fieldIndex: integer, isModal: boolean, doReturn: boolean) {
+  constructor(scene: BattleScene, switchType: SwitchType, fieldIndex: integer, isModal: boolean, doReturn: boolean) {
     super(scene);
 
+    this.switchType = switchType;
     this.fieldIndex = fieldIndex;
     this.isModal = isModal;
     this.doReturn = doReturn;
@@ -38,11 +42,13 @@ export class SwitchPhase extends BattlePhase {
       return super.end();
     }
 
-    // Skip if the fainted party member has been revived already. doReturn is
-    // only passed as `false` from FaintPhase (as opposed to other usages such
-    // as ForceSwitchOutAttr or CheckSwitchPhase), so we only want to check this
-    // if the mon should have already been returned but is still alive and well
-    // on the field. see also; battle.test.ts
+    /**
+     * Skip if the fainted party member has been revived already. doReturn is
+     * only passed as `false` from FaintPhase (as opposed to other usages such
+     * as ForceSwitchOutAttr or CheckSwitchPhase), so we only want to check this
+     * if the mon should have already been returned but is still alive and well
+     * on the field. see also; battle.test.ts
+     */
     if (this.isModal && !this.doReturn && !this.scene.getParty()[this.fieldIndex].isFainted()) {
       return super.end();
     }
@@ -57,7 +63,8 @@ export class SwitchPhase extends BattlePhase {
 
     this.scene.ui.setMode(Mode.PARTY, this.isModal ? PartyUiMode.FAINT_SWITCH : PartyUiMode.POST_BATTLE_SWITCH, fieldIndex, (slotIndex: integer, option: PartyOption) => {
       if (slotIndex >= this.scene.currentBattle.getBattlerCount() && slotIndex < 6) {
-        this.scene.unshiftPhase(new SwitchSummonPhase(this.scene, fieldIndex, slotIndex, this.doReturn, option === PartyOption.PASS_BATON));
+        const switchType = (option === PartyOption.PASS_BATON) ? SwitchType.BATON_PASS : this.switchType;
+        this.scene.unshiftPhase(new SwitchSummonPhase(this.scene, switchType, fieldIndex, slotIndex, this.doReturn));
       }
       this.scene.ui.setMode(Mode.MESSAGE).then(() => super.end());
     }, PartyUiHandler.FilterNonFainted);
diff --git a/src/phases/switch-summon-phase.ts b/src/phases/switch-summon-phase.ts
index 525f74e896f..eb1e089543b 100644
--- a/src/phases/switch-summon-phase.ts
+++ b/src/phases/switch-summon-phase.ts
@@ -12,29 +12,30 @@ import i18next from "i18next";
 import { PostSummonPhase } from "./post-summon-phase";
 import { SummonPhase } from "./summon-phase";
 import { SubstituteTag } from "#app/data/battler-tags";
+import { SwitchType } from "#enums/switch-type";
 
 export class SwitchSummonPhase extends SummonPhase {
-  private slotIndex: integer;
-  private doReturn: boolean;
-  private batonPass: boolean;
+  private readonly switchType: SwitchType;
+  private readonly slotIndex: integer;
+  private readonly doReturn: boolean;
 
   private lastPokemon: Pokemon;
 
   /**
      * Constructor for creating a new SwitchSummonPhase
      * @param scene {@linkcode BattleScene} the scene the phase is associated with
+     * @param switchType the type of switch behavior
      * @param fieldIndex integer representing position on the battle field
      * @param slotIndex integer for the index of pokemon (in party of 6) to switch into
      * @param doReturn boolean whether to render "comeback" dialogue
-     * @param batonPass boolean if the switch is from baton pass
      * @param player boolean if the switch is from the player
      */
-  constructor(scene: BattleScene, fieldIndex: integer, slotIndex: integer, doReturn: boolean, batonPass: boolean, player?: boolean) {
+  constructor(scene: BattleScene, switchType: SwitchType, fieldIndex: integer, slotIndex: integer, doReturn: boolean, player?: boolean) {
     super(scene, fieldIndex, player !== undefined ? player : true);
 
+    this.switchType = switchType;
     this.slotIndex = slotIndex;
     this.doReturn = doReturn;
-    this.batonPass = batonPass;
   }
 
   start(): void {
@@ -64,7 +65,7 @@ export class SwitchSummonPhase extends SummonPhase {
 
     const pokemon = this.getPokemon();
 
-    if (!this.batonPass) {
+    if (this.switchType === SwitchType.SWITCH) {
       (this.player ? this.scene.getEnemyField() : this.scene.getPlayerField()).forEach(enemyPokemon => enemyPokemon.removeTagsBySourceId(pokemon.id));
       const substitute = pokemon.getTag(SubstituteTag);
       if (substitute) {
@@ -94,7 +95,7 @@ export class SwitchSummonPhase extends SummonPhase {
       ease: "Sine.easeIn",
       scale: 0.5,
       onComplete: () => {
-        pokemon.leaveField(!this.batonPass, false);
+        pokemon.leaveField(this.switchType === SwitchType.SWITCH, false);
         this.scene.time.delayedCall(750, () => this.switchAndSummon());
       }
     });
@@ -105,7 +106,7 @@ export class SwitchSummonPhase extends SummonPhase {
     const switchedInPokemon = party[this.slotIndex];
     this.lastPokemon = this.getPokemon();
     applyPreSwitchOutAbAttrs(PreSwitchOutAbAttr, this.lastPokemon);
-    if (this.batonPass && switchedInPokemon) {
+    if (this.switchType === SwitchType.BATON_PASS && switchedInPokemon) {
       (this.player ? this.scene.getEnemyField() : this.scene.getPlayerField()).forEach(enemyPokemon => enemyPokemon.transferTagsBySourceId(this.lastPokemon.id, switchedInPokemon.id));
       if (!this.scene.findModifier(m => m instanceof SwitchEffectTransferModifier && (m as SwitchEffectTransferModifier).pokemonId === switchedInPokemon.id)) {
         const batonPassModifier = this.scene.findModifier(m => m instanceof SwitchEffectTransferModifier
@@ -130,7 +131,7 @@ export class SwitchSummonPhase extends SummonPhase {
          * If this switch is passing a Substitute, make the switched Pokemon match the returned Pokemon's state as it left.
          * Otherwise, clear any persisting tags on the returned Pokemon.
          */
-        if (this.batonPass) {
+        if (this.switchType === SwitchType.BATON_PASS || this.switchType === SwitchType.SHED_TAIL) {
           const substitute = this.lastPokemon.getTag(SubstituteTag);
           if (substitute) {
             switchedInPokemon.x += this.lastPokemon.getSubstituteOffset()[0];
@@ -174,8 +175,13 @@ export class SwitchSummonPhase extends SummonPhase {
       pokemon.battleSummonData.turnCount--;
     }
 
-    if (this.batonPass && pokemon) {
+    if (this.switchType === SwitchType.BATON_PASS && pokemon) {
       pokemon.transferSummon(this.lastPokemon);
+    } else if (this.switchType === SwitchType.SHED_TAIL && pokemon) {
+      const subTag = this.lastPokemon.getTag(SubstituteTag);
+      if (subTag) {
+        pokemon.summonData.tags.push(subTag);
+      }
     }
 
     this.lastPokemon?.resetSummonData();
diff --git a/src/phases/turn-init-phase.ts b/src/phases/turn-init-phase.ts
index 92547878f12..2f1b539cdcf 100644
--- a/src/phases/turn-init-phase.ts
+++ b/src/phases/turn-init-phase.ts
@@ -32,7 +32,7 @@ export class TurnInitPhase extends FieldPhase {
           this.scene.unshiftPhase(new GameOverPhase(this.scene));
         } else if (allowedPokemon.length >= this.scene.currentBattle.getBattlerCount() || (this.scene.currentBattle.double && !allowedPokemon[0].isActive(true))) {
           // If there is at least one pokemon in the back that is legal to switch in, force a switch.
-          p.switchOut(false);
+          p.switchOut();
         } else {
           // If there are no pokemon in the back but we're not game overing, just hide the pokemon.
           // This should only happen in double battles.
diff --git a/src/phases/turn-start-phase.ts b/src/phases/turn-start-phase.ts
index 5c1af4228c6..b070abb390a 100644
--- a/src/phases/turn-start-phase.ts
+++ b/src/phases/turn-start-phase.ts
@@ -19,6 +19,7 @@ import { TurnEndPhase } from "./turn-end-phase";
 import { WeatherEffectPhase } from "./weather-effect-phase";
 import { BattlerIndex } from "#app/battle";
 import { TrickRoomTag } from "#app/data/arena-tag";
+import { SwitchType } from "#enums/switch-type";
 
 export class TurnStartPhase extends FieldPhase {
   constructor(scene: BattleScene) {
@@ -179,7 +180,8 @@ export class TurnStartPhase extends FieldPhase {
         this.scene.unshiftPhase(new AttemptCapturePhase(this.scene, turnCommand.targets![0] % 2, turnCommand.cursor!));//TODO: is the bang correct here?
         break;
       case Command.POKEMON:
-        this.scene.unshiftPhase(new SwitchSummonPhase(this.scene, pokemon.getFieldIndex(), turnCommand.cursor!, true, turnCommand.args![0] as boolean, pokemon.isPlayer()));//TODO: is the bang correct here?
+        const switchType = turnCommand.args?.[0] ? SwitchType.BATON_PASS : SwitchType.SWITCH;
+        this.scene.unshiftPhase(new SwitchSummonPhase(this.scene, switchType, pokemon.getFieldIndex(), turnCommand.cursor!, true, pokemon.isPlayer()));
         break;
       case Command.RUN:
         let runningPokemon = pokemon;
diff --git a/src/test/abilities/zen_mode.test.ts b/src/test/abilities/zen_mode.test.ts
index c7cbd9014e0..b4c60aa7a7f 100644
--- a/src/test/abilities/zen_mode.test.ts
+++ b/src/test/abilities/zen_mode.test.ts
@@ -18,6 +18,7 @@ import GameManager from "#test/utils/gameManager";
 import Phaser from "phaser";
 import { afterEach, beforeAll, beforeEach, describe, expect, test } from "vitest";
 import { Status, StatusEffect } from "#app/data/status-effect";
+import { SwitchType } from "#enums/switch-type";
 
 
 
@@ -113,7 +114,7 @@ describe("Abilities - ZEN MODE", () => {
       await game.phaseInterceptor.run(EnemyCommandPhase);
       await game.phaseInterceptor.run(TurnStartPhase);
       game.onNextPrompt("SwitchPhase", Mode.PARTY, () => {
-        game.scene.unshiftPhase(new SwitchSummonPhase(game.scene, 0, 1, false, false));
+        game.scene.unshiftPhase(new SwitchSummonPhase(game.scene, SwitchType.SWITCH, 0, 1, false));
         game.scene.ui.setMode(Mode.MESSAGE);
       });
       game.onNextPrompt("SwitchPhase", Mode.MESSAGE, () => {
diff --git a/src/test/moves/shed_tail.test.ts b/src/test/moves/shed_tail.test.ts
new file mode 100644
index 00000000000..a976a614792
--- /dev/null
+++ b/src/test/moves/shed_tail.test.ts
@@ -0,0 +1,56 @@
+import { SubstituteTag } from "#app/data/battler-tags";
+import { Abilities } from "#enums/abilities";
+import { Moves } from "#enums/moves";
+import { Species } from "#enums/species";
+import GameManager from "#test/utils/gameManager";
+import Phaser from "phaser";
+import { afterEach, beforeAll, beforeEach, describe, it, expect } from "vitest";
+
+describe("Moves - Shed Tail", () => {
+  let phaserGame: Phaser.Game;
+  let game: GameManager;
+
+  beforeAll(() => {
+    phaserGame = new Phaser.Game({
+      type: Phaser.HEADLESS,
+    });
+  });
+
+  afterEach(() => {
+    game.phaseInterceptor.restoreOg();
+  });
+
+  beforeEach(() => {
+    game = new GameManager(phaserGame);
+    game.override
+      .moveset([Moves.SHED_TAIL])
+      .battleType("single")
+      .enemySpecies(Species.SNORLAX)
+      .enemyAbility(Abilities.BALL_FETCH)
+      .enemyMoveset(Moves.SPLASH);
+  });
+
+  it("transfers a Substitute doll to the switched in Pokemon", async () => {
+    await game.classicMode.startBattle([Species.MAGIKARP, Species.FEEBAS]);
+
+    const magikarp = game.scene.getPlayerPokemon()!;
+
+    game.move.select(Moves.SHED_TAIL);
+    game.doSelectPartyPokemon(1);
+
+    await game.phaseInterceptor.to("TurnEndPhase", false);
+
+    const feebas = game.scene.getPlayerPokemon()!;
+    const substituteTag = feebas.getTag(SubstituteTag);
+
+    expect(feebas).not.toBe(magikarp);
+    expect(feebas.hp).toBe(feebas.getMaxHp());
+    // Note: Shed Tail's HP cost is currently not accurate to mainline, as it
+    // should cost ceil(maxHP / 2) instead of max(floor(maxHp / 2), 1). The current
+    // implementation is consistent with Substitute's HP cost logic, but that's not
+    // the case in mainline for some reason :regiDespair:.
+    expect(magikarp.hp).toBe(Math.ceil(magikarp.getMaxHp() / 2));
+    expect(substituteTag).toBeDefined();
+    expect(substituteTag?.hp).toBe(Math.floor(magikarp.getMaxHp() / 4));
+  });
+});