Harold is a red-orange fish with chubby cheeks who makes several cameo appearances, starting the episode "Ripped Pants."
He is a red-orange fish with light orange fins and chubby cheeks. He wears light blue swim trunks that sometimes have green flowers on them.
He first appears in the episode "Ripped Pants," roasting and eating marshmallows in Goo Lagoon when SpongeBob asks him if he could borrow some, to which he nods yes. He is also seen in "Hooky" as a cameo, saying his sandwich is a fried boot. In "Jellyfish Hunter," Fred puts Jellyfish Jelly in his Krabby Patty. In "New Digs," he wipes his mouth with SpongeBob's underwear. His name is revealed in "To Love a Patty" when Martha Smith calls him Harold. In "Spongicus," he is in the audience in the Chum Coliseum. He also appears to be eating spinach in chocolate spaghetti in calamari sauce in "Karate Star." He appears again in "Tutor Sauce," in which he makes a cameo appearance with Squidward, whacking him with a spatula for seemingly no reason. In "SpongeBob's Place," he is one of the Bikini Bottomites chanting "SpongeBob's Place!" after Squidward suggests to Mr. Krabs that he changes the name of the restaurant. His latest appearance is in "Trident Trouble," when he wishes the grass would grow, and when SpongeBob uses the trident to make it grow, the grass chases after Harold with his lawnmower. He is later seen mowing the grass again near the end of the episode.