Mettaton's most recognizable form, Mettaton changes from its robotic "calculator" like appearance to a much more human like one, giving it new attacks, ranging from leg attacks to disco balls firing lasers. It has a huge loss of durability, yet makes up for it with power. He is 6'4".
Dr. Alphys' ultimate creation. It contains all of Mettaton's programming from when he was designed as a human-hunting robot, and is his most powerful form as a result.
Not much is known about this form except a new design, and a cannon on one of his arms, because Chara easily took Mettaton NEO out with a single hit.