The Hairy Ape (1922) is an expressionist play by Eugene O'Neill about a brutish, unthinking laborer known as Yank as he searches for a sense of belonging in a world controlled by the rich. At first Yank feels secure as he stokes the engines of an oceanliner, and is highly confident in his physical power over the ship's engines.However, when the weak but rich daughter of an industrialist in the steel business refers to him as a "filthy beast," Yank undergoes a crisis of identity. He leaves the ship and wanders into Manhattan, only to find he does not belong anywhere—neither with the socialites on Fifth Avenue, nor with the labor organizers on the waterfront. Finally he is reduced to seeking a kindred being with the gorilla in the zoo and dies in the animal's embrace.

Eugene Gladstone O'Neill (October 16, 1888 – November 27, 1953) was an American playwright and Nobel laureate in Literature. His poetically titled plays were among the first to introduce into American drama techniques of realism earlier associated with Russian playwright Anton Chekhov, Norwegian playwright Henrik Ibsen, and Swedish playwright August Strindberg. The drama Long Day's Journey Into Night is often numbered on the short list of being among the finest American plays in the 20th century alongside A Streetcar Named Desire and Death of a Salesman.