Captain John Yossarian is a fictional character and the protagonist of the novel Catch-22 by Joseph Heller. He is a U.S. Army Air Forces B-25 bombardier during World War II, known for his strong desire to avoid combat missions. Yossarian is deeply troubled by the absurdity of war and the bureaucratic rules that govern it. Throughout the story, Yossarian grapples with the concept of Catch-22, a paradoxical rule that prevents him from escaping dangerous situations. His character embodies the struggle against the dehumanizing effects of war and the quest for personal survival amidst chaos.