Kaburamaru

Kaburamaru is a snake and animal guide belonging to the Serpent Hashira, Obanai Iguro. Kaburamaru is always seen wrapped around Obanai’s shoulder.

Appearance
Kaburamaru is a small white snake with reddish pink eyes and long hexagonal scales that adorn his body. He appears to be an individual of his species with albinism. He possesses two long fangs that, as well as the shape of his head, indicates that he is most likely venomous.

Personality
Kaburamaru seems to be a rather intelligent animal, not just an ordinary snake. In most situations, he is usually seen flicking his tongue to sense his surroundings while coiled around Obanai's neck. He also appears to be of similar personality to Obanai himself, as seen when he angrily hissed at Suma for chiding the Serpent Hashira for his late arrival to Yoshiwara. He also seems to be attached to Mitsuri Kanroji, as she was seen stroking Kaburamaru in the past, and when he seemingly shed tears during her death.

After Obanai's death, Kaburamaru appears to have mellowed out somewhat, as he was shown being entrusted to Sanemi Shinazugawa and later Kanao Tsuyuri, whereas he was initially always with Obanai from the beginning. He is also seen smelling Tanjiro Kamado's face in curiosity.

History
During his life in captivity to become a sacrifice to the Serpent Demon, Obanai found a small snake had slithered into his cell. Being the only living thing that didn't want him dead at the time, he took the snake in as a companion. Once he made his escape, he had the snake with him when he fled. The two would end up being rescued shortly after by the Flame Hashira of then, Shinjuro Rengoku.

Kaburamaru became a permanent companion to Obanai, always coiled around him during his career as a Demon Slayer and eventually as the Serpent Hashira.

Rehabilitation Training Arc
During Tanjiro's trial, Obanai and Kaburamaru were perched in a tree in the garden of the Demon Slayer Corps' headquarters. Kaburamaru is seen looking around as his owner questioned that Giyu Tomioka should be punished along with Tanjiro for his aid in protecting the former's demon sister Nezuko Kamado. Kaburamaru is present when Obanai pins down Tanjiro to prevent him from intervening in Sanemi Shinazugawa's attempt to prove Nezuko's potential danger to humans and is seen later that evening in a meeting with the Hashira and Kagaya Ubuyashiki.

Entertainment District Arc
In the aftermath of the battle against the dual holders of Upper Rank Six, Obanai arrived to Yoshiwara to survey the extent of the damage with Kaburamaru. He discovered that Tengen Uzui has defeated the demons but the Serpent Hashira reminded him that his accomplishment is still insignificant due to Upper Six being the least of the Upper Ranks. One of Tengen's wives, Suma, reprimands Obanai for his late arrival to Yoshiwara, causing Kaburamaru to hiss at the young women, scaring her.

Abilities
Overall Abilities: Kaburamaru is far more intelligent than the average snake, as he is capable of understanding human language and following commands. He also serves as an animal guide for Obanai, who is himself partially blind, being able to put his own sensorial abilities to use and relay the information to his owner, granting him greater perception. Kaburamaru also seems to be exceptionally well trained as he was not only capable of discerning the many lethal attacks of Muzan Kibutsuji himself, he was also intelligent enough to grab one of Yushiro's paper talismans in mid-air in between Muzan's attacks, feats that left the Demon King flabbergasted that an animal like him could detect him so well. Most impressively, Kaburamaru was able to survive the encounter with the Demon King, completely unscathed, despite all the carnage unleashed by Muzan's rampage.