Frankenstein Conquers the World(1965)

 Frankenstein Conquers the World(1965)

During WWII, a human heart taken from a certain lab in Europe 

(Dr. Frankenstein's) is kept in a Japanese lab, when it gets 

exposed to the radiation of the bombing of Hiroshima. The heart 

grows in size, mutates and sprouts appendages, and eventually 

grows into a complete body and escapes. Later, a feral boy with 

a certain physical deformity (a large head with a flat top) is 

captured by scientists who refer to the boy as Frankenstein. The 

creature grows to the height of 20 feet, escapes again, fights 

police and army, and is practically indestructible. Later, a 

reptilian monster goes on a rampage. Eventually the Frankenstein 

creature and the reptile face off in a terrible battle. (IMDB QQQ-2)