Mugaru appeared in Terror of Mechagodzilla as the supreme leader of the second attempt by the Black Hole aliens to conquer Earth, successor to the identical-looking Kuronuma. Acting on the advice of his second-in-command Tsuda, Mugaru recruited Dr. Shinji Mafune and his daughter Katsura, and their "pet" dinosaur Titanosaurus, to the aliens' cause. Mugaru is thought to have been killed by jumping off a cliff on Manazura Island into the sea while fleeing from Interpol agents led by Jiro Murakoshi.