Gelman is a school bully at Third Street School.
Gelman is a tall, fat ten-year-old boy with messy red hair and freckles. He wears a black T-shirt, grey pants, and sneakers.
Gelman is always looking for kids to bully for no reason. His previous target was a boy named Stemple , until he moved away. Since then he started picking on Gus. Out of every kid he bullied Gus was his main target, until Gus stood up for himself, however in "A Great State Fair ", he starts being a little nicer to Gus and stops bullying. He's not shown to have any friends, but on a few occasions he hangs out with Lawson and his gang. He is the most feared bully in Third Street School. Everyone is scared of him, even Spinelli. Though this situation changes after the episode "Gus' Last Stand ." He also gets snapped when he narrowly misses Gus' plan to put him in a cage (Or, as Gus said, 'Get Gelmanized')
- It remains unknown whether Gelman is his first name or last name.
- Gelman is voiced by Justin Shenkarow who also voiced another bully named Harold Berman from Hey Arnold.