Zuboo

His main form.

Zuboo was a demon only seen in Amon: Apocalypse of Devilman OVA. He changed form many times and had highly psychopathic behavior.

Amon: Apocalypse of Devilman

Zuboo's first form.

Zuboo is first seen near the beginning chasing down the young Devilman Yumi, whilst disguised as a salaryman. He corners her and reveals his demon form, but he is almost immediately ambushed my Miko another Devilman.

Zuboo changes form and quickly gets back on his feet and starts to smash Miko against a wall while Yumi watches, terrified. With Zuboo preoccupied with attacking the two Devilmen, he fails to notice Akira slowly walking towards him. Before Zuboo can react, Akira punches him in the face. Enraged Zuboo changes form again into a large ball and tries to run Akira down, but Akira strikes the demon again, sending him flying around. As he charges into him, Akira strikes Zuboo in the chest, with the demon using his elastic powers to bite Akira's left shoulder. Suddenly, Zuboo begins to rotate, then Akira absorbs the demon into his fist, ending Zuboo for good.