The Meaning of Life, the Universe, and Everything.
Piranhas are aggressive mobs that spawns in jungle rivers.
They represented by group of small fishes, but it is actually, one mob 1x1 size.
They will make jungles is bit more dangerous place to hangout.
Jungles in real world is a very dangerous place. In Minecraft it most safest place, because aggressive mobs do not spawn so often like in other biomes (because of the trees). So let jungles be more dangerous because of natural fauna.
piranhas can drop mobs body parts it would be like they ate mobs but not bloody! they can drop random stuff they ate. gorillas hmm, uhh, they can drop some thing they eat, their fur to make cool gorilla armor but it has the same armor stats like leather armor,