This papercraft is Skull Man, a Robot Master created specially for combat with balanced offense and defense by Dr. Cossack while he was working for Dr. Wily in Mega Man 4, the paper model is created by Julio Cesar KOALAZERO.
He attacks with shots from his arm cannon, and can generate a skull-shaped energy shield called the Skull Barrier for protection. Skull Man only moves or attacks when Mega Man does the same; however, he doesn't move if Mega Man only jumps, instead firing his buster.
Much like Ring Man before him, Skull Man was made solely for the purpose of fighting. With this in mind, he is a good strategist, and is meticulous in his attention to detail- particularly with planning his combat methods. However, he lacks skill in other areas having only been taught to fight, and tends to be socially awkward; often alienating others by acting in bad taste. Befitting his morbid theme, Skull Man is also a huge fan of horror movies. His weakness is Dust Crusher due to the fact that the projectile can get easily lodged in his workings. [Source: wikia]