The World Famous French Foreign Legionnaire is one of Snoopy's alter egos. He first appears on August 22, 1965 where Snoopy steals one of Charlie Brown's handkerchiefs to make a Sahara kepi. He is finally identified as a member of the French Foreign Legion a few weeks afterwards. He later adds a column of recruits (Woodstock and the rest of the Beagle Scouts) and refers to himself as the "World Famous Sergeant-Major of the French Foreign Legion".
Snoopy's Legionnaire fantasies are based around the novel Beau Geste by P.C. Wren and its many film adaptations. He refers to himself as "Beau" Snoopy, the novel's tragic hero, and his aim is almost always to retake and hold Fort Zinderneuf for the French.
In real life, Fort Zinderneuf is most often Snoopy's doghouse, though other buildings occasionally serve this role including the Brown house, the kids' school building, the golf course clubhouse, and even sandcastles. The Sahara desert is represented by the neighborhood kids' sandboxes (Snoopy: "Smallest desert I've ever seen.") or the beach. In several sequences of strips, Snoopy marches his troops through every sand trap at nearby Ace Country Club, once resulting in Charlie Brown having to rake out their footprints from all 80 bunkers. When he finishes the exhausting task, he discovers that Snoopy and the birds have returned and are again marching through the sand traps.
In a storyline from April 1986, while imagining themselves as Legionnaires, Snoopy and his friends somehow get hold of an operational and loaded cannon which they fire at "Fort Zinderneuf". To their shock and dismay, the cannon ball destroys Snoopy's doghouse, blasts the top off of Lucy's psychiatry booth, and comes to rest atop Schroeder's broken piano.