Dick Miller was an American actor (Gremlins, The Little Shop of Horrors, Death Race 2000) known for his films with Roger Corman. He later appeared in the films of directors who began their careers with Corman, including James Cameron and Joe Dante.
He was, in the words of Cult Movie Stars (1991) a “scene-stealer in low-budget horror films”.
Above is the enormously amusing film The Little Shop of Horrors (1960, above) in which Miller plays a carnation-eating (“I’m crazy about kosher flowers”) regular customer of the florist in which the film is set.
Minute 34:48 has Jack Nicholson come in as a masochistic client to the dentist. That scene was later done by  with Steve Martin as the dentist and Bill Murray as the client.
I’ve seen quite some films with mister Miller, all entertaining, unassuming and unpretentious.