What is "yossarian"

Capt. John Yossarian is a fictional character, the protagonist of Joseph Heller's satirical novel Catch-22 and its sequel Closing Time. In Catch-22, Yossarian might be a 28-year-old captain in the 256th squadron of the Army Air Forces where he could serve as a B-25 bombardier stationed on the small island of Pianosa off the Italian mainland during World War II. Yossarian's exploits are based on the experiences of the author: Heller was also a bombardier in the Army Air Corps, stationed on an island off the coast of Italy during World War II.