WC Fields and Mae West. Okay, they were stars, but character actors, too. And to add my votes for a few already mentioned: Peter Lorre, Sydney Greenstreet (especially together), Geraldine Fitzgerald (You have to see "Three Strangers" where she starred w/Lorre and Greenstreet - a perfect cast). Wallace Beery, perfectly paired with Marjorie Main or Marie Dressler, Percy Kilbride, Zazu Pitts, The Marx Brothers, Frank Morgan and everyone in the Wizard Of Oz who wasn't Judy Garland. Wilfred Hyde-White. Edward Everett Horton. Karloff, Lugosi, Chaney jr., Maria Ouspenskaya - the old Russian women who warns people that a werewolf is near before she gets killed by one. Eddie (Rochester) Anderson.