Hal Archer

The legendary empire of the lost continent of Mu reappears to threaten the world with domination. While countries unite to resist, an isolated World War II Captain has created the greatest warship ever seen, and possibly the surface world's only defense.

Through an experiment by Dr. Stewart with animal cells, a monster is created that is given the name Frankenstein. He is a gentle giant, but he escapes his guards and was supposedly killed on a mountain. After several years, a ship off the coast is attacked by a green monster, where the people think of Frankenstein. The green monster attacks the fortified country, in which the army is then called in for help. When a brown monster suddenly appears, Dr. Stewart understands that his Frankenstein was not killed, but has reproduced.