Absolutely not to be confused with Larry Buchanan’s dreadful It’s Alive! (1969), Larry Cohen’s first horror film is the perfect example of one of his greatest strengths, the ability to take even the most ridiculous notion and somehow make it work. In future films, he’d give us a mad alien messiah loose on the streets of New York City (God Told Me To (1976)); a giant Aztec bird/lizard/deity similarly stalking the city (Q (1982)); and food that disconcertingly eats us rather the other way round (The Stuff (1985)) and here it’s a wild tale of mutant killer babies.

In Los Angeles, expectant couple Frank (John P. Ryan) and Lenore Davis (Sharon Farrell) and their first son Chris (Daniel Holzman) are awaiting the arrival of baby number two. But at the hospital, their child is born horribly deformed and abnormally strong. He slaughters the delivery team and escapes through a skylight, leaving Lenore traumatised and Frank fearful that the child has been abducted. Lt. Perkins (James Dixon) is assigned to investigate the killings while the Davis’ struggle with intrusive attention from the press, Frank becoming increasingly estranged from Lenore as he tries to distance himself from his new son who continues to commit grisly murders. With nervous pharmaceutical company executives and the police eager for the child’s death (Lenore had been taking contraceptive pills for many years that might be linked to the child’s abnormalities), Frank is horrified to find that Lenore is sheltering the infant in the basement of their house. It eventually flees into the sewers where it’s cornered by the police and where Davis finally comes to realise that he still loves his son no matter what.

No-one made films quite like Larry Cohen – conceptually daring, bold and fiercely intelligent, he often walked the very thin line between the audacious and the absurd, but attacked his own remarkable scripts with such verve, commitment and confidence that he helped us past even the most outré of moments with consummate ease. In It’s Alive, as with all of his films, he plays the audacity with a completely straight face and stages scenes of genuine horror along side moments that are knowingly silly with a very light touch. The scene of the expectant fathers in the waiting room making light of their nerves, and Davis looking wistfully at the room full of new-borns contrast starkly with the sudden horror moments later when Lenore (“what’s wrong with my baby?”) tries to convince the delivery team, that something’s wrong and an orderly staggers bleeding and dying through a doorway.

But above the witty humour (the cops, guns drawn, circle a perfectly normal toddler mistaking him for the mutant baby) and the grim horror (Davis’ stumbling into the massacre in the delivery room is genuinely unsettling), it’s the emotional arc that Davis describes throughout the film that really hits home the most. It first, he’s horrified at the thought that his child might have been abducted; then he becomes emotionally numbed as he tries to distance himself from the baby as it goes on its murderous rampage, even resorting to blaming Lenore (“look what your child did”); and finally, in a remarkable moment set in the sewers, has an epiphany and realises that he loves his son no matter what. It’s a quite remarkable depth of character that you rarely found in a 70s horror film – there were some other fine examples but they were few and far between – and it works largely because of the excellent performance from Ryan as the conflicted Davis. Particularly his tearful speck to his son at the end and his desperate attempts to get the police to spare him. The entire cast is very good but it’s Ryan who emerges head and shoulders above the rest. He was rarely this good here or in the film’s first sequel (he can always be seen in Futureworld (1976), The Postman Always Rings Twice (1981) and The Right Stuff (1983) among many others) and he’s given great support from Farrell, Guy Stockwell and Andrew Dugan as doctor and Michael Ansara as the police captain.

It’s Alive was made in the wake of the ground-breaking Roe vs. Wade U.S Supreme Court decision that legalised abortions across all of the States from January 1973, giving the film an added resonance at the time of its release that hasn’t quite continued to this day. There’s talk of contraceptives being the cause for the mutation, but we never do find out what causes it. Perhaps it’s simply beyond understanding. The first of the film’s two sequels takes a more evolutionary approach but here we’re as clueless at the end as to what caused it as the hapless Davis’ and the baby’s pursuers and tormentors.

Elsewhere, Davis musings about the way that Frankenstein and his creation are constantly being mixed up, positioning himself as the scientist and the baby as the monster., is no mere fan service from Cohen. One of It’s Alive many big questions is over the moral quandary around who the real monsters are in the film – the baby, a bald, fanged monstrosity created by Rick Baker, the pharmaceutical company who may or may not have caused it but who panic anyway, the trigger happy police or even Davis and his initial hatred for his offspring. These sorts of ambiguities became a hallmark of Cohen’s horror films, another reason that marked him out as one of the very best, most intelligent and most fearless of genre filmmakers of the decade.

It’s Alive was followed by a brace of sequels which, rather than merely rehash the same old plot, at least tried to expand on the themes and ideas of the first film. It Lives Again (1978) finds Davis working to save the several other mutant children that have appeared since the death of his son while It’s Alive III: Island of the Alive (1987) picks up the story several years later with a group of other mutant children being quarantined on a remote island. The original film was remade by Josef Rusnak in 2009 and promptly vanished without trace.