The scene where the big boss of Engulf and Devour slowly goes rabid... culminating in him biting one of his men, growling like a bulldog and eventually howling like a wolf.
Marty Feldman trying to catch an elevator.
The trio chasing Paul Newman.
In the hospital, taking his medicine. Mel Brooks puts the pill in his mouth, and he takes an entire glass of water with it. When he opens his mouth to complain that the medicine never works, the pill is still in plain sight, stuck to his tongue.