Kevin is a bear who lived in the Backyardigans and Frontyardigans' neighborhood. He is always nice to the gang in real life. But he always pretends to be a villain no matter which episode he appears in. He has a twin sister named Tina who also only plays villains.
Whenever Kevin and Tina were defeated, the other female characters would say, "You are a very bad bear." (or if together, "You are very bad bears.")
Due to episodes not needing a villain, and episodes that have other characters playing more superior villains, Kevin doesn't appear very often.
He seems to have a friendly rivalry with Austin.