diff --git a/public/images/pokemon/exp/back/381-mega.png b/public/images/pokemon/exp/back/381-mega.png
index 811231cbc..d865e64c3 100644
Binary files a/public/images/pokemon/exp/back/381-mega.png and b/public/images/pokemon/exp/back/381-mega.png differ
diff --git a/src/battle-scene.ts b/src/battle-scene.ts
index 98c1fc83e..c3f920acb 100644
--- a/src/battle-scene.ts
+++ b/src/battle-scene.ts
@@ -893,7 +893,26 @@ export default class BattleScene extends SceneBase {
 		//this.pushPhase(new TrainerMessageTestPhase(this, TrainerType.RIVAL, TrainerType.RIVAL_2, TrainerType.RIVAL_3, TrainerType.RIVAL_4, TrainerType.RIVAL_5, TrainerType.RIVAL_6));
 
 		if (!waveIndex && lastBattle) {
-			const isNewBiome = !(lastBattle.waveIndex % 10) || (this.gameMode.isDaily && lastBattle.waveIndex === 49);
+			let isNewBiome = !(lastBattle.waveIndex % 10) || ((this.gameMode.hasShortBiomes || this.gameMode.isDaily) && (lastBattle.waveIndex % 50) === 49);
+			if (!isNewBiome && this.gameMode.hasShortBiomes) {
+				let w = lastBattle.waveIndex - ((lastBattle.waveIndex % 10) - 1);
+				let biomeWaves = 1;
+				while (w < lastBattle.waveIndex) {
+					let wasNewBiome = false;
+					this.executeWithSeedOffset(() => {
+						wasNewBiome = !Utils.randSeedInt(6 - biomeWaves);
+					}, w << 4);
+					if (wasNewBiome)
+						biomeWaves = 1;
+					else
+						biomeWaves++;
+					w++;
+				}
+
+				this.executeWithSeedOffset(() => {
+					isNewBiome = !Utils.randSeedInt(6 - biomeWaves);
+				}, lastBattle.waveIndex << 4);
+			}
 			const resetArenaState = isNewBiome || this.currentBattle.battleType === BattleType.TRAINER || this.currentBattle.battleSpec === BattleSpec.FINAL_BOSS;
 			this.getEnemyParty().forEach(enemyPokemon => enemyPokemon.destroy());
 			this.trySpreadPokerus();
diff --git a/src/data/pokemon-species.ts b/src/data/pokemon-species.ts
index 72850fb05..ed55bbf4d 100644
--- a/src/data/pokemon-species.ts
+++ b/src/data/pokemon-species.ts
@@ -1782,7 +1782,7 @@ export function initSpecies() {
       new PokemonForm("Fancy Pattern", "fancy", Type.BUG, null, 0.3, 2.5, Abilities.SHIELD_DUST, Abilities.COMPOUND_EYES, Abilities.FRIEND_GUARD, 200, 38, 35, 40, 27, 25, 35, 255, 70, 40, false, ""),
       new PokemonForm("Poké Ball Pattern", "poke-ball", Type.BUG, null, 0.3, 2.5, Abilities.SHIELD_DUST, Abilities.COMPOUND_EYES, Abilities.FRIEND_GUARD, 200, 38, 35, 40, 27, 25, 35, 255, 70, 40, false, ""),
     ),
-    new PokemonSpecies(Species.SPEWPA, 6, false, false, false, "Scatterdust Pokémon", Type.BUG, null, 0.3, 8.4, Abilities.SHED_SKIN, Abilities.NONE, Abilities.FRIEND_GUARD, 213, 45, 22, 60, 27, 30, 29, 120, 70, 75, GrowthRate.MEDIUM_FAST, 50, false, false,
+    new PokemonSpecies(Species.SPEWPA, 6, false, false, false, "Scatterdust Pokémon", Type.BUG, null, 0.3, 8.4, Abilities.SHED_SKIN, Abilities.SHED_SKIN, Abilities.FRIEND_GUARD, 213, 45, 22, 60, 27, 30, 29, 120, 70, 75, GrowthRate.MEDIUM_FAST, 50, false, false,
       new PokemonForm("Meadow Pattern", "meadow", Type.BUG, null, 0.3, 8.4, Abilities.SHED_SKIN, Abilities.NONE, Abilities.FRIEND_GUARD, 213, 45, 22, 60, 27, 30, 29, 120, 70, 75, false, ""),
       new PokemonForm("Icy Snow Pattern", "icy-snow", Type.BUG, null, 0.3, 8.4, Abilities.SHED_SKIN, Abilities.NONE, Abilities.FRIEND_GUARD, 213, 45, 22, 60, 27, 30, 29, 120, 70, 75, false, ""),
       new PokemonForm("Polar Pattern", "polar", Type.BUG, null, 0.3, 8.4, Abilities.SHED_SKIN, Abilities.NONE, Abilities.FRIEND_GUARD, 213, 45, 22, 60, 27, 30, 29, 120, 70, 75, false, ""),
diff --git a/src/game-mode.ts b/src/game-mode.ts
index f06c65826..0ac3f0503 100644
--- a/src/game-mode.ts
+++ b/src/game-mode.ts
@@ -20,6 +20,7 @@ interface GameModeConfig {
   hasTrainers?: boolean;
   hasFixedBattles?: boolean;
   hasNoShop?: boolean;
+  hasShortBiomes?: boolean;
   hasRandomBiomes?: boolean;
   hasRandomBosses?: boolean;
   isSplicedOnly?: boolean;
@@ -33,6 +34,7 @@ export class GameMode implements GameModeConfig {
   public hasTrainers: boolean;
   public hasFixedBattles: boolean;
   public hasNoShop: boolean;
+  public hasShortBiomes: boolean;
   public hasRandomBiomes: boolean;
   public hasRandomBosses: boolean;
   public isSplicedOnly: boolean;
@@ -174,7 +176,7 @@ export class GameMode implements GameModeConfig {
 
 export const gameModes = Object.freeze({
   [GameModes.CLASSIC]: new GameMode(GameModes.CLASSIC, { isClassic: true, hasTrainers: true, hasFixedBattles: true }),
-  [GameModes.ENDLESS]: new GameMode(GameModes.ENDLESS, { isEndless: true, hasRandomBiomes: true, hasRandomBosses: true }),
-  [GameModes.SPLICED_ENDLESS]: new GameMode(GameModes.SPLICED_ENDLESS, { isEndless: true, hasRandomBiomes: true, hasRandomBosses: true, isSplicedOnly: true }),
+  [GameModes.ENDLESS]: new GameMode(GameModes.ENDLESS, { isEndless: true, hasShortBiomes: true, hasRandomBosses: true }),
+  [GameModes.SPLICED_ENDLESS]: new GameMode(GameModes.SPLICED_ENDLESS, { isEndless: true, hasShortBiomes: true, hasRandomBosses: true, isSplicedOnly: true }),
   [GameModes.DAILY]: new GameMode(GameModes.DAILY, { isDaily: true, hasTrainers: true, hasNoShop: true })
 });
\ No newline at end of file
diff --git a/src/phases.ts b/src/phases.ts
index 038907d94..f59c6516e 100644
--- a/src/phases.ts
+++ b/src/phases.ts
@@ -1049,7 +1049,8 @@ export class SelectBiomePhase extends BattlePhase {
     };
 
     if ((this.scene.gameMode.isClassic && this.scene.gameMode.isWaveFinal(this.scene.currentBattle.waveIndex + 9))
-      || (this.scene.gameMode.isDaily && this.scene.gameMode.isWaveFinal(this.scene.currentBattle.waveIndex)))
+      || (this.scene.gameMode.isDaily && this.scene.gameMode.isWaveFinal(this.scene.currentBattle.waveIndex))
+      || (this.scene.gameMode.hasShortBiomes && !(this.scene.currentBattle.waveIndex % 50)))
       setNextBiome(Biome.END);
     else if (this.scene.gameMode.hasRandomBiomes)
       setNextBiome(this.generateNextBiome());
@@ -1086,8 +1087,10 @@ export class SelectBiomePhase extends BattlePhase {
         });
       } else
         setNextBiome(biomes[Utils.randSeedInt(biomes.length)]);
-    } else
+    } else if (biomeLinks.hasOwnProperty(currentBiome))
       setNextBiome(biomeLinks[currentBiome] as Biome);
+    else
+      setNextBiome(this.generateNextBiome());
   }
 
   generateNextBiome(): Biome {