Rondo Hatton, who played the monstrous Creeper in this film and in House of Horrors (1946), was actually handsome as a young man, but later in life became disfigured by acromegaly, a form of gigantism brought about by unnaturally high levels of human growth hormone produced by a disease of the pituitary gland.
Rondo Hatton passed away before the film was released. Universal was so embarrassed by its shameless exploitation of Hatton's disfiguring illness (which led to his death) that it sold all rights to the finished film to "B" studio Producers Releasing Corporation (PRC).
Although produced by Universal Pictures, the company was in the process of a complicated merger with William Goetz's International Pictures (merger completed July 31, 1946). To complicate matters, J. Arthur Rank's United World Pictures had a hand in the studio's management since the previous November, when this picture was still in production. With the impending change in management, studio brass dictated that "B" pictures would no longer be produced. As a result, this poorly made low-budget horror film became an embarrassment and it was sold to notoriously cheapjack PRC Pictures after completion.
Completed in November 1945, released by PRC a year later on October 1, 1946 (Rondo Hatton's final performance). This was a sequel to House of Horrors (1946), completed in September 1945. In between, Hatton shot The Spider Woman Strikes Back (1946) in October, all three features only seeing release after his death in February 1946. Hatton had first played The Creeper in the Sherlock Holmes feature The Pearl of Death (1944), unrelated to the two follow-ups.
This film has sometimes been claimed to have elements of Rondo Hatton's real-life story in its script, but the only similarities are that both Hal Moffet and Hatton were college football stars and both got acromegaly from exposure to toxic chemicals--though the real Hatton got it not from an accident in a chemistry lab but from a poison gas attack against his unit when he was serving with the US Army in World War I.