Kieper is depicted with a tan complexion and short clumps of hair. He wears a red shirt with a horizontal yellow stripe and yellow cuffs, a black sleeveless biker jacket, dark gray jeans, and red and white high-top sneakers.
He is often a member of Binky's team in sports that opposes Arthur's team, such as roller hockey. His reputation is often harsh and he would get into various fights with people. From time to time, he wrestled with Rattles. He has also been mean to Arthur, such as grabbing at his sweater
While it's unknown where he lives or what his house looks like, the inside of Kieper's house was shown during the episode Sue Ellen Moves In where he was talking on the phone with the other kids about Sue Ellen and what their opinion is of her. The interior of his house appears to be yellow for either the kitchen or living room.