In the novel Peril at End House, Commander George Challenger is a friend of Nick Buckley. He is a commander in the English Navy. He is described as a "red-faced man with a rolling carriage" who carries "his hands half clenched by his side". He has a soft spot for Nick, and wishes to marry her but Nick tells Poirot neither of them "has a bean".
He has an uncle, who is a doctor in Harley Street. It is later revealed that Challenger, together with his uncle, was a supplier of cocaine. He supplied his friends Nick Buckley and Freddie Rice with cocaine, which was hidden in their wristwatches.
George Challenger is played by John Harding in the film adaptation of Peril at End House in Series 2 of ITV's Agatha Christie's Poirot drama series. The portrayal is faithful to the original except for a few minor details. In the adaptation, Challenger owns a yacht even though, as Nick also said about him, he doesn't have a bean. For Poirot this was grounds for suspicion. In the film he is arrested by Japp at the end of the show whereas in the novel he was allowed to go.
In the NHK anime adaptation The Mystery of End House, Challenger has a slightly smaller role than in the original novel. The entire sideplot of him handling a drug peddling operation together with his uncle Dr MacAllister is totally omitted and his uncle does not appear at all. However the details of Nick's will are changed from the original. Here, her estate is divided equally between Freddie Rice, Charles Vyse and Challenger. As such, when Poirot began to investigate the attempts to kill Nick, he considered Challenger to be one of three plausible suspects. The voice actor behind the character of George Challenger is not credited.