Dwight Frye (1899-1943) was a terrific actor in everything I've ever seen him in. He was excellent at portraying deranged (particularly memorable as Renfield in 1931's Dracula) or otherwise neurotic, unusual, and/or deformed characters, though it's rather unfortunate that he became so typecast in those type roles, since he also was a talented "regular" dramatic actor, but really didn't get much utilized in that capacity, ultimately winding up with a very limited career as a result.