Anthony Kiedis has been with the Red Hot Chili Peppers since its birth in the early 198os. The only other consistent Red Hot Chili Pepper band member since the band's inception is Flea (née Michael Peter Balzary), the band's funky bassist.
However, Flea's foray into acting is not unusual. He has memorable roles in Back to the Future II as McFly's boss who fires him over a television screen, and as a german nihilist in The Big Lebowski. His role in Psycho is a small cameo as he plays a quiet store clerk who is shooed to go to lunch as Julianne Moore interrogates Viggo Mortensen regarding her sister's (Anne Heche) disappearance. He is relegated with a special credit as his character actually has a full name, Bob Summerfield, instead of a typical credit of 'store clerk'.
Although, that credit probably exists because it is in the original Hitchcock thriller and not because Flea's character is awesome enough to warrant a last name.