War of the Colossal Beast (a.k.a. Revenge of the Colossal Man and The Colossal Beast) is a 1958 black-and-white science fiction film, written, produced, and directed by Bert I. Gordon for his Carmel Productions, and starring Dean Parkin, Sally Fraser, and Roger Pace. It is the sequel to Gordon's earlier The Amazing Colossal Man (1957) and was distributed theatrically on June 30, 1958 by American International Pictures as the bottom half of a double feature with Attack of the Puppet People (1958). (Historian Bill Warren lists the double feature's release date as August 7, 1958.)

Plot

Upon hearing of several recent robberies of food delivery trucks in Mexico, Joyce Manning, Army Lt. Colonel Glenn Manning's sister, becomes convinced that her brother survived after being exposed to radiation from an atomic bomb (as seen in The Amazing Colossal Man). Along with Army Major Mark Baird and scientist Dr. Carmichael (Russ Bender), Joyce goes to Mexico to look for Glenn and finds that he has, in fact, survived, but was left disfigured and nearly mindless by the trauma of his fall. Glenn is eventually captured, drugged by the Army, and transported back to the United States. He is able to escape again and goes on a rampage through Los Angeles and Hollywood. He nearly kills a school bus full of children. Joyce reasons with him, and he slowly is brought back to his senses. Now realizing what he has become and what he has done, Glenn commits suicide by electrocuting himself on high-voltage power lines near the Griffith Observatory.