Trivia

Among the materials used by Les Bowie to embellish the monster were bovine entrails and tripe.

The film achieved a degree of notoriety Stateside when in 1956 the parents of Stewart Cohen attempted to sue Chicago's Lake Theater and distributors United Artists for negligence after their nine-year-old son died of a ruptured artery at a double-bill of this and The Black Sleep (1956) on Sunday 28th October, during the opening sequence of the Hammer movie. Cohen entered the Guinness Book of Records as the only known case of someone literally dying of fright at a horror film (although he had been unwittingly living with an undiagnosed heart condition).

Actress, cake decorator and future fiancée of Paul McCartney, a young Jane Asher plays the little girl trying her unsuspecting best to befriend a transmogrifying Victor Carroon (Richard Wordsworth). The chance encounter is reminiscent of James Whale's classic Frankenstein (1931), wherein Little Maria and the Frankenstein monster meet.

Nigel Kneale had several reservations about this adaptation of his tale, conceding it was well-directed and pared down with pace from his original story line. He deplored the use of US actors Brian Donlevy (finding him far too unsympathetic and implausible as the lead role) and Margia Dean. Les Bowie's tripe-based realisation of the creature, also vexed the writer. Kneale was further infuriated by the BBC, who refused him any involvement or remuneration for this commercial use of his work, since as a contracted staff member all rights remained with the Corporation and not the individual.

Val Guest heavily reworked Richard Landau's story draft (which assumed Quatermass would be British so changed Briscoe into a USAF Flight Surgeon), particularly tailoring the dialogue to compliment Donlevy's punchy no-nonsense acting style, which he believed helped to sell the more obscure SF plot elements to audiences.