Walter is the name of William Tell's son in the Swiss legend.
Although he is not called out by name, Walter appears in episode 307 of The Muppet Show, where he performs in an act with his father. The onstage act, which occurs offscreen, involves the father attempting to shoot an apple off the boy's head with an arrow. Unfortuantely, Walter seems unaware of his father's inability to perform with the jitters and ends up with an arrow through his head. Luckily, it went in one ear and out the other. Not allowing good food to go to waste, Walter proceeds to eat the undamaged apple.