Short and bald, with a slight hunch to his shoulders, he was immediately recognizable by his distinct appearance, his nasal voice, and his pronounced New York City accent.

[citation needed] Beginning in 1937, Glass worked regularly in films, helped by friends such as producer John Houseman.

[citation needed] He was a frequent member of Columbia Pictures' short subjects department roster, and a favorite of directors Jules White and Del Lord.

He did not appear in any films released between 1942 and 1947, possibly because of military service, but he generally worked in a handful of films almost every year thereafter, playing small roles and bit parts, including additional Three Stooges shorts Hokus Pokus (1949), Three Hams on Rye (1950) and Flagpole Jitters (1956).

Highlights of Glass's film career include playing Doc, the drugstore owner, in West Side Story (1961), Popcorn in Blake Edwards's thriller Experiment in Terror (1962), and bad guy Leopold W. Gideon in Stanley Donen's Charade (1963).

In 1957, he appeared as Jackson, an arms dealer to Indians, in an episode of the syndicated western series Boots and Saddles.

He appeared in the syndicated crime drama Sheriff of Cochise and the ABC western series The Rebel, starring Nick Adams.

[7] He played Sol Cooper on the Diahann Carroll vehicle Julia from 1968 to 1971, and was nominated in 1969 for an Emmy Award for his performance in the "A Little Chicken Soup Never Hurt Anybody" episode.

[citation needed] Glass also played Uncle Moe Plotnick on the short-lived series Bridget Loves Bernie (1972–1973).