In 1980–81, David toured the country with John Houseman's The Acting Company in productions of "A Midsummer Night's Dream" and Samuel Beckett's "Waiting for Godot". Less than two years later, he went on to star as Childs, opposite Kurt Russell in John Carpenter's "The Thing", and his lengthy on-screen career had begun. In the 1980s run of "Mister Rogers' Neighborhood", he portrayed Keith the Southwood Carpenter in the Neighborhood of Make-Believe segments. He also played Keith, the game coin collector in an episode where Rogers and a small child learn to play the arcade game "Donkey Kong".