Russell Cosby is Bill's younger brother and the youngest of the gang. He plays a xylophone with cans and spoons. Him, Mushmouth, Dumb Donald and Rudy wear hats. He hates going to the doctor. He tends to give away secrets that the gang does not want him to say. He's known for not being on good terms with Rudy and always finds his behavior annoying. In both the original series and movie, Russell always wears a heavy jacket, boots, and Ushanka winter hat despite what the weather is.