Ultraman - 1966

As soon as our planet is threatened by alien reptiles and giant critters, the entire planet is based upon the Science Patrol, a defense agency equipped with weaponry and vehicles to combat the dangers. Whenever the Science Patrol's weaponry is unsuccessful and all hope has been lost, certainly one among their members, Hayata, transforms into a giant alien called Ultraman to overcome the colossal menace threatening the Earth, unbeknownst to one other Science Patrol members, who are unaware of his secret identity.