Nudibranches are exotic pets 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 nudibranches in real life, which look like sea slugs. Puffy Fluffy is a nudibranch, nudibranches are become unstably dangerous near cats and/or cat sounds and tortures Gary scaring him since Gary makes cat sounds.