Search: jack nicholson little shop
Why: On Buzzfeed "25 Celebrities You Never Knew Were In Classic Movies":
19. Jack Nicholson in 'Little Shop of Horrors'
Answer: Well, this is something:
That was from 1960. The original film concept is thought to be based on a 1932 story "Green Thoughts" by John Collier.
The More You Know: Here's Bill Murray playing the sameish character in 1986. This one was directed by Frank Oz.