Zōffy's Superweapon, Zetton

Zōffy's weapon to eradicate the Solar System, the Ultimate Celestial Suppression Weapon Zetton, is a truly colossal robot that utterly dwarfs Ultraman. As the Ultra soon finds out, Zetton is able to to resist all of his attacks, and boasts some fearsome weapons of its own, which it unloads all at once to deal with Ultraman quickly when its point-defence system alone isn't quite enough.

Example of:
Humongous Mecha