Puffer Fish

Puffer Fish are a group of fish who turn into a inflate when intimated, They are currently green and orange varieties. Judging by official blog, they seem easily frightened. A particularly large member of their species is found in Level 2 of Aqua Grabber as the boss guarding the level's valuable purple crystals (Amethyst).

Behaviour
Puffer fishs seem to be easily scared and will inflate to their full size if penguins approach them.

Giant Pufferfish
A particularly large member of their species, named Puff Daddy, lives in a cave at the bottom of the Soda Seas. It sucks in water then lets it out, in a similar fashion to that of the mythological Charybdis, pulling and pushing the Aqua Grabber craft. It is orbited by two inflated pufferfish. Puff Daddy is named after a rapper called Puff Daddy.