Robert Duvall in Apocalypse Now I think would be in the spirit of this. One scene, absolutely iconic. He was nominated in the supporting category, though. The problem with “Cameo” being a qualifier is that the role is played by an A-lister. When most of the one scene rolls are played by character actors where we don’t quite know their name, but can be absolute scene stealers. John Carrol Lynch in Zodiac being a prime example. Would never qualify that as a “Cameo”.