An American character actor best known for his role as Count Dracula lookalike "Grandpa", opposite Fred Gwynne's and Yvonne De Carlo's characters on the CBS television series The Munsters from 1964 to 1966 and its subsequent film versions. Later in life, he was also a restaurant owner, political candidate, and radio broadcaster. His acting career begins the well-documented portion of his life. He worked in burlesque and vaudeville theaters, then on Broadway in the dramas The Night Circus (1958) and One More River (1960) and as the character Moe Shtarker in the musical comedy Do Re Mi (1962).

His earliest television work includes appearances on the Beverly Garland crime drama Decoy and The Phil Silvers Show. From 1959–63, he appeared in four episodes of Naked City. Lewis' first well-known television role was as Officer Leo Schnauser on the NBC sitcom Car 54, Where Are You? from 1961–63, also starring Fred Gwynne (Lewis reprised the role in the 1994 movie of the same name). In the series, Lewis first played Al Spencer the Auto Body Man in two early first-season episodes before landing the more familiar role of Officer Schnauser. But he is best remembered as "Grandpa" on The Munsters, which ran on CBS from 1964–66.