John Callahan (born in 1964) is a retired American professional wrestler, best known for his time in the World Wrestling Federation (WWF) starting in 1979. Trained by Killer Kowalski, he wrestled against iconic figures such as Hulk Hogan, Iron Sheik, Junkyard Dog, and Roddy Piper. Throughout his career, he portrayed several characters, including "Big John Callahan," "Baltimore Terror," and "American Ninja." He was a two-time New England Heavyweight Champion and a New England Tag Team Champion with Big City Mike. He retired in 1999 after suffering a hip injury. In 2010, he was inducted into the New England Professional Wrestling Hall of Fame. After retiring, he worked as Circulation Director for the Milford Daily News and currently appears as an announcer for Showcase Pro Wrestling under the character "Sgt. Muldoon."
