He is a short fish with a blue tie, light blue shirt, and reddish-brown pants. He works for the Bikini Bottom Department of Health. He appears to be inexperienced at his job and does not care if he is not doing it properly.
Squidward calls the health department to file a complaint against SpongeBob's Place, prompting him to come the next day. He and Health Inspector Yellowtail arrive at the restaurant near the end, as it is illegal to sell food inside pineapples. However, Carl does not care about city health codes and eats a patty from SpongeBob's Place, prompting Yellowtail to toss the patty and remind him about the laws. Carl scornfully walks off stating that Yellowtail is not the boss of him, although Yellowtail hollers back that he is.