Shtick: Psycho henchman.

Oh sure, you know and love him now as the grandfatherly psycho clown, but back in his days as a young psycho extra, ol’ Sid was one of the backlot gang. The hair went, the beard came, but Sid kept the faith, glowering and drawling (on those few occasions when he had any lines at all) through any number of roles with no nuance whatsoever. And with a mug like that, who needs it?