Iguva=41

Iguva=41 (also spelled Iguvua=41 or similar) is an Elder Lich, an undead magic caster created by Ainz Ooal Gown as part of his experiments with undead in the New World.

He appears in Overlord Season 2 (around the Lizardmen arc) as the field commander of an undead army sent by Cocytus to conquer/annihilate the lizardmen tribes. He's arrogant yet cautious, utterly devoted to Ainz, and offers his enemies a "painless death" if they surrender.

Appearance-wise, he's a grotesque, skeletal undead figure reeking of decay, draped in an old luxurious robe over his bony body.

He serves as a mid-boss/antagonist in that storyline, using spells like fire arrows and summoning, but is ultimately defeated by the combined efforts of the lizardmen heroes (Zaryusu, Crusch, and Zenberu). In his final moments, he begs Ainz for forgiveness for his failure.