Panini is a pink bunny/cat (cabbit). She has her ears tied like pigtails/ponytail and has rose colored eyes. Her regular outfit is a yellow dress with light green polka-dots and a light green heart in the middle of the dress. She has green shoes and a polka-dotted hair band that ties her ears. Her appearance changes when she is angry to an extreme degree. During this time while she is in her "anger form", she resembles a cat more than a rabbit. She has black fur, her irises and nose are fuschia, and her scleras are green. Also during this time, her outfit resembles Chowder's.
Also stated by the creator, she was going to be named Borlotti, have pointy ears and wear something with her face being the only thing not covered. Instead of being in love with Chowder, she would be a bully to him. C.H Greenblatt described them like Tommy and Angelica Pickles from Rugrats.
However, the creator dropped the pointy ears idea as he felt it didn't fit with the drawing styles of Chowder, and he wasn't fond with that behavior as he thought he needed to make her more "sweeter and cuter". He then thought of a concept of Panini being in love with Chowder, since Chowder is not old enough to fall in love with females, according to Greenblatt, this aspect would frustrate Chowder "in a more fun way".
Panini is very loyal to Ms. Endive and gets punished by her whenever she fails her, according to "The Apprentice Games". Panini always obeys Ms. Endive's demands, even if it means hurting Chowder.
Panini is also a good Sniffleball player. In one episode, Panini thought that she and Chowder had a Bluenana Baby. Panini also has a dark side, like when she violently forced Chowder to hold her hand and when she almost beat Gazpacho into a pulp. She sometimes seems to dislike Gorgonzola due to his constant bullying of Chowder.
Panini is the pink cat-rabbit-bear hybrid fo the show. She has a love interest with Chowder and is now a future wife of him. She can be curious, loveable and cute sometimes.