FusionDex

It fishes for small aquatic Pokémon and underwater plants using its tails, which will react to movement by lunging and biting. Its cell structure is so similar to water molecules that it can effectively meld into water and become invisible within it.

Giraeon underwent a spontaneous mutation and grew fins and gills that allow them to live underwater. A Giraeon is an herbivore--it eats grass and tree shoots.