Fungo Fish

The Fungo Fish is the Jellyfish analogue of the Hardmode Underground Underwater Mushroom Biome. As such, they are a jellyfish with bigger numbers in the health, defense, and damage departments, but otherwise the same drill. Their damage, especially, is notable for being extremely high - they deal more damage than even late-game bosses.

They have a unique banner drop.

They are immune to the Confused debuff.