Dr Manzeo discovers that living creatures can be made into giants by feeding them a "prehistoric" variety of swamp moss. He is stopped by a giant-sized Jim who forces him to turn over the antidote to restore all of Manzeo's experimental subjects (and Jim himself) to normal size.; Murray Spence attempts to sell a machine that he claims will transform $10 bills into fifties. He foolishly plies his con from the very room where magician and spiritualist Leon Frammis lived his last days. Frammis punishes Spence by exposing him as a fraud and finally taking over his body.; Real estate developer Jason Jaxon intends to fill in Bubi's swamp and build a tract of homes. However he is defeated by Bubi who calls upon his friends, the creatures of the swamp, to thwart Jaxon's plans.