Destromon

Digimon World 3
Destromon resembles an enormous, red, robotic dinosaur-like creature. This Digimon is armed with an enormous number of energy cannons on its wrists and shoulders; its main weapon is located on its chest. It is the result of the fusion between Vemmon with an experimental battleship known as "Juggernaut". Vemmon is teleported aboard the craft and fuses with it, forming the mighty Destromon. The monstrous creature makes its power known as it decimates a naval fleet with ease, before flying toward the nearest major city.

Long believed by characters of the game to be unstoppable in every way, its only weakness was discovered by the game's protagonists after defeating its controller. They shut down the terrible machine before it could completely destroy the city it was attacking, and the monstrous Digimon self-destructed.

It is impossible to fight Destromon in the game, as it only appears in cutscenes.