Gurendaizâ, Gettâ Robo jî, Gurêto Majingâ - Kessen! Daikaijû

When a mysterious gigantic monster, called Dragosaur, appears from the depth of the oceans and threatens the world, a team of super-robots from Japan is activated and sent out to defeat it: Grendizer, The Great Mazinger and Getter G. - IMDb