Pufferfish

Pufferfish are aquatic mobs in Minecraft, typically found in warm and lukewarm ocean biomes. While they don't actively seek out other mobs to attack, they defensively inflate when players, axolotls, or non-aquatic mobs get too close, dealing damage and inflicting Poison on those who approach. Pufferfish have three stages: unpuffed, semi-puffed, and fully puffed, with the level of inflation affecting the damage and poison duration inflicted. Players can capture pufferfish using a water bucket, obtaining a 'bucket of pufferfish,' which will not despawn naturally. In the game, pufferfish, besides being defensive mobs, can also be obtained through fishing or by killing guardians/elder guardians. They are important for crafting potions of water breathing. However, eating a pufferfish leads to poison, hunger, and nausea, making it inadvisable to consume them directly. Moreover, pufferfish do not swim in schools in Minecraft and are relatively unique creatures in the game.