Puffer Shrimp

A cosmetic pet, so the only real questions are whether you like the look and whether you are willing to give up the buff slot for it. The pufferfish drifts along inside its bubble and keeps pace with you, which reads better underwater than most pets do.

The PB and J line in the tooltip is the joke. It is shorthand for two things that always turn up together, borrowed from the peanut butter and jelly sandwich, so the pet is telling you it has no intention of leaving.