One day, a bunch of cats fell into the ocean. Since then they have evolved into a new type of cat: the CatFish! No, not the actual fish. It's a cat with fish-like features.
This specific type of CatFish is a DeepSea CatFish. They somehow managed to adapt to the extreme pressure in the deeper parts of the ocean. The DeepSea CatFish was first discovered when a camera was sent deep into the ocean. Researchers have managed to bring a few to land for research purposes. It appears that they can survive on land as well as any other CatFish. They are also more aggressive than the other two types, making them less suitable as pets.