Konga
(1961)

Dr. Charles Decker comes back from Africa after spending a year there. During that year he discovered a way of growing animate matter to an enormous size. He tests his theory on a baby chimpanzee, which he uses to gain vengeance on his many enemies. When it reaches gigantic proportions it creates havoc in London city.

Kronos
(1957)

A large saucer shaped object crashes into the ocean near to Mexico. The object, Kronos, is actually a giant machine which foretells of the danger of overconsumption of energy resources. It attacks power stations and drains them of their energy. Eventually, Kronos becomes larger and larger in size and consumes more and more energy threatening the Earth's very existence.