Bonnie and Billy are Caucasian humans. Bonnie has long dark brown hair with bangs and brown irises. She is typically seen wearing a violet hair ribbon, a purple shirt with a white vest over it, a dark purple skirt, white sneakers, and purple socks. Billy has short light brown hair with bangs and blue irises. He wears a blue and purple shirt with a red 1 on the front, dark purple pants, red and white sneakers with white strings, and white socks.
Bonnie and Billy often do their best to keep the Popples from trying to make a mess over important things, but don't always succeed. However, Bonnie's regulations over the Popples being around tend to be more strict than Billy's.