Erdmann began his career on stage, performing in theaters in Berlin, Vienna, and elsewhere. Possessing a raspy vocal quality, Erdmann has worked steadily in dubbing. He was the German voice of Mr. T on The A-Team and dubbed James Earl Jones in The Sandlot, Bill Cobbs in Get Low, Charles Durning in Desperation, Paul Bartel in Joyride, and Nicholas Bell in Dark City. On TV, he dubbed Stephen Root on NewsRadio, Paul Dooley as Whizzer and guest roles on ALF, minor parts on The Incredible Hulk, and the Dalek Emperor on Doctor Who. In animation, he dubbed the Comic Book Guy and others on The Simpsons, Dr. Zoidberg on Futurama, the wolfman in The Nightmare Before Christmas, Kraven and Red Skull on the 1990s Spider-Man series, and various Roman soldiers in the Asterix films.