The place seems to be a parody of Chuck E. Cheese's. The building briefly appears in the most recent intro. The building was destroyed and burned by Yelpers in "You're Not Yelping", but it was rebuilt sometime afterwards, as seen in the song "The Yelper Special".
The restaurant is a building made of bricks and resembles an old-fashioned train with smokestacks and wheels. Old wooden barrels and a wooden porch are outside, like a general store would have in the 1800s. It has an illuminated sign on the roof which says "Whistlin' Willy's", and under it says "Pizza gultch. Est. 1986". At the top of the sign is an old man with a pizza hat and has lights around it that flash.
Inside, the place has tables at the center, and arcade machines and monitors at the walls. There is a mascot, "Willy", in a costume that entertains the patrons and whistles a lot; he doesn't give the pizza until you whistle. There appears to be a VIP lounge which has a man that guards it with a velvet rope barrier, as seen in the episode "Quest for Ratings".
- "Child Abduction is Not Funny" - The boys go here after "winning" the baseball match.
- 'Quest for Ratings" - The Super School News team come here after failing to get enough viewers.
- "The Losing Edge" - The boys come here after winning their baseball games.
- "Bloody Mary" - Randy and Stan come here after Randy is "cured" of his alcoholism.
- "Le Petit Tourette" - Cartman speaks about his tourettes.
- "Margaritaville" - Kyle speaks to the boys about how one of them will betray him.
- "You're Getting Old" - Stan has his birthday party here.
- "Ass Burgers" - Stan's new house is next to Whistlin' Willy's.
- "You're Not Yelping" - Whistling Willy's leads a movement against Yelpers, which ends with the restaurant being destroyed.