David Dawson Palmer (August 27, 1936 - September 10, 1972) was a stuntman and stage actor. Palmer, a former basketball player worked mainly for producer Irwin Allen. His large stature led to him portraying many monsters, aliens and cyborgs on Allen's TV shows, most notably Lost in Space. He was in fact known on that show as the "resident monster." Palmer can be recognized in three episodes of Lost in Space because his face was shown. He played Keel in "The Space Croppers," a solder in "The Lost Civilization" and IDAK Omega 17 in "Revolt of the Androids." He was killed in September 10, 1972 in a car accident. Wikipedia credits him as the horned mutant in “One of Our Dogs Is Missing,” but IMDb credits Charles Dierkop.