<P> Captain John Francis Xavier McIntyre appears in the novels, the film (played by Elliott Gould), the M * A * S * H TV series (Wayne Rogers), and the Trapper John, M.D. series (Pernell Roberts). He is one of the main characters in the M * A * S * H TV series during the first three seasons, and the central character of the latter series . His nickname comes from an incident in which he was caught having sex with a woman in the lavatory aboard a Boston & Maine Railway train; who claimed in her defense that "he trapped me!" </P> <P> In the book and the film, Trapper John is a graduate of Dartmouth College (having played quarterback on the school's football team) and serves as thoracic surgeon of the 4077th . In the film, he has a dry, sardonic deadpan sense of humor, while in the M * A * S * H TV series he is more of a class clown . Trapper spends much of his time on the series engaging in mischief with Hawkeye Pierce, with the two playing practical jokes on majors Frank Burns and "Hot Lips" Houlihan, drinking, and trying to seduce women . While Trapper expresses great love for his wife and daughters, he also fraternizes with the nurses a great deal, with no pretense of fidelity . </P> <P> In the film, Hawkeye and Trapper are given roughly equal focus, but in the TV series the character became more of a sidekick to the character of Hawkeye . This frustrated Rogers, and in combination with a dispute over the terms of the contract for the fourth season, he quit the show; the character of Trapper was abruptly transferred back to the U.S. between seasons . The character of B.J. Hunnicutt was created to replace him . </P> <P> The character returned to television in 1979 in the medical drama series Trapper John, M.D. Now played by Pernell Roberts, the character is depicted in the then - present day as Chief of Surgery at a San Francisco hospital . This version of the character is in continuity with the film rather than the TV series, but no other characters from either production appear in this series, making Trapper John the only M * A * S * H character to be depicted on - screen in (what was then) the present day . Trapper John, along with The Mary Tyler Moore Show's Lou Grant, thus became one of a handful of 1970s television characters to be successfully adapted from situation comedy to drama . </P>

Who took trapper john's place on mash