A deranged scientist invents a serum that causes plants and animals to grow dramatically. He uses it to make a chimpanzee the size of a gorilla, then hypnotises it to murder his enemies. However, he is unable to control the ape, while ultimately attains gigantic proportions. Horror, with Michael Gough, Margo Johns and Jess Conrad.

Dr. Decker returns from Africa after a year, presumed dead. In that year, he discovered a way of growing plants and animals to an enormous size. He brings back a baby chimpanzee to test out his theory. As he has many enemies at home, he decides to use his chimp, 'Konga', to 'get rid of them'. Then Konga grows to gigantic proportions and wreaks havoc all over London!