One of Snoopy's favorite games is to imagine that he is fighting in World War I as a flying ace who does battle with the Red Baron. Snoopy's first appearance as a World War I fighter-pilot was in the Peanuts comic strip from October 10, 1965. Snoopy's World War I fantasies were first depicted on television in the animated special, It's the Great Pumpkin, Charlie Brown, first broadcast on October 27, 1966.
Snoopy's friend Woodstock and his siblings, Belle and Spike have also participated in the game. However, when Snoopy's brother Marbles visits the neighborhood, in a storyline from October 1982, he finds Snoopy's behavior very confusing and is unable to understand why Snoopy calls his doghouse a Sopwith Camel.
Amongst the children in the Peanuts cast, Marcie has been the most eager participant in Snoopy's World War I game, happy to take on the role of the "French lass" who falls for the fighter-pilot. In a storyline from February 1986, she nurses him when he falls sick during the 1918 influenza epidemic.
The topic of World War I is dealt with more seriously in the Peanuts animated television special, What Have We Learned, Charlie Brown?, in which Charlie Brown, Linus van Pelt, Marcie, Peppermint Patty, Snoopy and Woodstock visit the site of a World War I battle in Belgium. Linus recites the World War I poem, In Flanders' Field before asking Charlie Brown if mankind has learnt anything from war.