Horror journeyman Larry Cohen, writer and director of numerous quirky horror projects, made his first foray into the genre with this low-budget cult favorite about a murderous mutant baby on a suburban rampage.
The story opens with a delivery-room massacre as the newborn child of Frank and Lenore Davies (John P. Ryan and Sharon Farrell) answers the doctor's slap by tearing him to pieces -- along with a few other medical personnel -- before fleeing the hospital for whereabouts unknown.
The subsequent hunt for the killer baby creates a rift between Frank, who wants the child destroyed, and Lenore, whose maternal instincts convince her that her child is not deliberately homicidal but merely frightened and defending itself.
The baby's bloody rampage continues with several murders (including the creepy scene in which the terrible tyke savages the neighborhood milkman), until it is cornered by Frank and a police task-force. At the crucial moment, Frank has a sudden change of heart and tries to defend the infant from the police.
Despite painfully low production values that render the monster scenes a bit silly (Rick Baker's creepy-looking but inarticulate baby model was simply pulled along on a string), Cohen's concept shines through, presenting a skewed but sincere interpretation of family values that could only be pulled off in the horror genre (see also Wes Craven's The Hills Have Eyes for another example).
The script makes passing suggestions that the mutation was a result of an inadequately tested fertility drug, a concept explored more fully in the sequel It Lives Again and quite extensively in the third installment, Island of the Alive.