|List of species|
Nudibranchs are exotic pets only featured in the episode "A Pal for Gary." They are sold at a streetside stand by a gypsy. However, they have not appeared in any episode besides this one and they look nothing like nudibranchs in real life, which look like sea slugs. Puffy Fluffy is a nudibranch purchased by SpongeBob. Nudibranchs are hostile around other pets, especially cats.
They are cute, fluffy creatures with long eyelashes and dimples. They come in the colors light purple, aqua, and light green. All have the same eye color.
Giant, slimy, angry beasts with multiple tongues with mouths (referencing either of the movies "Alien" or '"Tremors") that correspond with their original colors. They turn into these creatures when around cats, probably to show that they are the dominant species of that particular territory.
- Puffy Fluffy the Nudibranch, in harmless form, has a fish-like appearance with a fin and fish tail rather than a slug appearance. However, this appearance can be seen in their evil form, but still possess a fin.