Grendizer, Getter Robo G, Great Mazinger: Decisive Battle! The Great Sea Monster

Dragonsaurus, a colossal sea monster, emerges from nowhere to terrorize the ocean depths. Great Mazinger, Grendizer, and the Getter Robo G team unite to confront this formidable threat. However, their mission grows perilous when Dragonsaurus swallows Boss Borot and makes its way towards Tokyo. Source: ANN