Ainz Ooal Gown has the appearance of an Overlord, an undead skeleton creature who is devoid of skin and flesh. He tends to mainly wear an elaborate, jet-black academic gown adorned with golden and violet edges. When he has no clothes on, his whole body alone is purely made up of just his bones. He also has a dark red orb floating under his ribs that emanates a feeling of dread.
Furthermore, he has a type of tiny dark red glow radiating from inside his empty eye sockets. Sometimes, however, that glow can become largely intensified, leading it to elicit faint reddish flames flickering about in both his two eyes.
Additionally, Ainz has a dark halo-like object glimmering right behind his head. In his dark warrior persona as Momon, Ainz wears a fully jet-black body armor adorned with purple and golden markings. Not only that, but he also wears a red cape out of admiration for Touch Me. He is equipped with two large swords on his back while carrying them behind him.