The Ulcer was a man who lived in Hollywood, and spent much of his life watching people bargain away their talents for fame and fortune. The experience made him so pessimistic, so cynical, that he literally became an ulcer in his own stomach. The show room where he supposedly spent his years became encased in his organs, with his heart and stomach juices below the stage, and himself a large, grotesque growth with a face latched to the wall. He lured people to the room, and offered fabulous prizes for performing for him if he liked their act. If he did not, he got heart burn, and dropped them into his stomach acid to be digested.
When Courage, Muriel, and Eustace drop into this room fromt he street above, he offers Eustace a golden truck, and Muriel a life like that of her favourite actress, Dolores Delores. They both fail his test, and are dropped into the stomach acid. Courage demands he give them back, and the ulcer asks if he would be willing to perform for a prize. not believing Courage would really perform just to get his family back, the ulcer tells him that if he succeeds in pleasing him, he, Courage, may name his prize.
Courage performs a tarzan act, and crashes through the floor into the stomach juice, throwing up Muriel and Eustace before they can be dissolved. The ulcer, moved by the sincerity of Courage's generosity and selflessness, has a heart attack, which Courage saves him from. He then reverts back into his original self, the organs making up the room regressing back into him, leaving a man in a white suit, and a commonplace looking show room.