This was the first science fiction film to be shot in three-color Technicolor, and it was nominated for a Special Effects Oscar.

It's about a mad scientist in the South American jungle who develops a machine to shrink animals. When he thinks his colleagues are getting in his way, he shrinks the down to one fifth of their normal size.

In one scene, the tiny shrunken people are threatened by a normal-sized alligator that looks like an enormous monster to them. The woman distracts it while the men collect wood. They set the wood on fire and throw at the gator which runs back into the river.