William Newell was a different kind of side kick for a serial hero. Usually they were either funny and totally inept, like Lee Ford, or non funny and a help to the hero, like Richard Fiske. Newell somehow managed to be both kinds at once. He was at times funny and inept, yet was also able to convey seriousness and be able to help out the hero on occasion.
He was in two serials in his acting career. He was Man Friday to Mala's jungle secret agent in Republic's "Robinson Crusoe of Clipper Island" (1936) and helped Robert Wilcox, whether masked or not, to track down the "Mysterious Doctor Satan" (1940). In both serials Newell would be at times a major klutz who seemed to be unable to walk into a room and remain standing upright, and yet pulled the hero's bacon out of the fire, sometimes literally, on numerous occasions.
Always a busy character player, Newell had major roles in many low budget films like "The Mandarian Mystery" (1937) and "The Invisible Killer" (1940). He was also a familiar face that popped up in a surprising number of big budget films; "The Bride Came C.O.D." (1941), "Lady in the Lake" (1946), and "Escape From Fort Bravo" (1953) to name a few.