I have a idea for a new Minecraft mob:

Adding deep sea isopod species such as Bathynomus giganteus or another large aquatic isopod would be great. Here's a few details of the mob:

It would be a passive mob and would swim away from its attacker.

It would eat seagrass like cows do with grass.

It would spawn in any ocean biome.

It would drop it's shell when killed witch could be used to craft armor.

Thanks for reading this!