Obanai Iguro (伊い黒ぐろ 小お芭ば内ない Iguro Obanai?) is a major supporting character of Demon Slayer: Kimetsu no Yaiba. He is a Demon Slayer of the Demon Slayer Corps and the current Serpent Hashira (蛇へび柱ばしら Hebi Bashira?).

Obanai is a fairly muscular man of short stature and a pale complexion. He has straight-edged black hair of varying lengths, the longest reaching down to his shoulders and the shortest stopping at his cheekbones, which he wears down with two shorter strands hanging between his eyes. His eyes are almond-shaped and tilt upwards on the far sides, and are unusual due to Obanai possessing heterochromia—his right eye is yellow and his left eye is turquoise. He is partially blind, barely able to see out of his right eye.

Obanai's mouth is also unusual: when he was twelve, it was forcefully cut from its corners to his ears to make it appear more like that of a snake, leaving a large wound that he keeps hidden under the bandage he wears over his lower face.