Blowfish

A blowfish is a species of fish from the planet Earth.

When Aquaman was giving the Krim family a tour of the ocean, he showed the Balunians a blowfish, and showed them that they aren't much different than them. He scratches the animal's belly and it grows in size. He then tells them that when in danger, it can inflate to three times his size.

Known blowfish

 * Puffer