Kaburamaru

Kaburamaru is a mid-sized albino Japanese rat snake whose eyes are a reddish pink, with notable fangs jutting from either side of his mouth and a body whose scales and belly are both whitened by his condition. Possessing intelligence well beyond a normal reptile, he keeps flicking his tongue to take in his surroundings as he winds about Obanai's neck.

The snake's moods echo his master's. He hissed in anger at Suma when she chided the Serpent Hashira for being late at Yoshiwara, while showing plain fondness for Mitsuri Kanroji and shedding tears as she lay dying. After Obanai's passing, the creature grows gentler and eventually sniffs with curiosity at Tanjiro's face.

The pair first crossed paths during Obanai's imprisonment, when he was kept as a sacrifice meant for the Serpent Demon. A small snake found its way into his cell, and since it was the only living thing that did not want him dead, he adopted it as a companion and brought it with him when he fled. Soon after, both were saved by the Flame Hashira of that time, Shinjuro Rengoku.

From that day forward Kaburamaru stayed beside Obanai across his life as a Demon Slayer and his ascent to Serpent Hashira, attending Hashira gatherings, looking over the wreckage at Yoshiwara, and plunging into the Infinity Castle with him when Muzan pulled the Corps underground.

Able to grasp human words and follow orders, Kaburamaru serves as eyes for the half-blind Obanai, passing along what his own senses pick up to widen his master's awareness. His conditioning showed itself to be remarkable in the final fight, where he traced Muzan's deadly storm of strikes and plucked one of Yushiro's paper charms from mid-air, a feat that left the demon king astonished.

Astonishingly, the snake came through all of Muzan's slaughter without a scratch. Three months after the demon king fell, Sanemi gave Kaburamaru over to Kanao, who commented on how bright the animal was. The kanji of his name carry the senses of arrowhead and round, and the species he resembles is treated in Japan as an omen of good fortune.