The 14th of 16 children born to a New York air-conditioner repairman and his wife, Henry Richard Hall was nicknamed "Huntz" because of his Teutonic-looking nose. At the ripe old age of one year, Huntz made his stage debut in Thunder on the Left. He went on to attend New York's Professional Children's School, perform in radio programs and at least one experimental TV broadcast, and sing with a youthful quintette; the last activity came to an end when he "ruined" his voice hawking peanuts at Madison Square Garden.
In 1935, Hall was cast as slum-kid Dippy in Sidney Kingsley's Dead End, repeating the role in the 1937 screen version. Together with his fellow "Dead End Kids" Leo Gorcey, Gabriel Dell, Billy Halop, Bobby Jordan and Bernard Punsley. Hall was signed by Warner Bros in 1938. In between such Warners' assignments as Angels With Dirty Faces (1938) and They Made Me a Criminal (1939), Hall co-starred with Halop, Dell, Punsley and Leo Gorcey's brother David in Universal's Little Tough Guy, the first of many "Dead End Kid" spin-offs. During his years at Universal, Hall began developing his trademarked goofy comic style, which came to full fruition when he was reunited with Leo Gorcey in Sam Katzman's East Side Kids series at Monogram. Previously, his character name (and character) had changed from film to film: at Monogram, Hall was consistently cast as Gorcey's perennial punching bag Glimpy. Occasionally, he accepted non-"East Side Kids" assignments in the mid-1940s, earning high critical praise for his performance as Carraway in Lewis Milestone's A Walk in the Sun.