Chachamaru

Chachamaru is a feline familiar that assists in Tamayo's medical research with Demon blood.

Appearance
Chachamaru is a small, tricolor calico cat with black, white and brown spots. He has big amber eyes. On his back, he wears a brown box with a syringe created by Tamayo with the purpose of collecting demons' blood. Around his neck, he wears a necklace with a paper talisman that was made and given by Yushiro, which he uses to hide with Yushiro´s Blood Demon Art.

History
No information is given on the cat, it is simply introduced as Tamayo's familiar used as a transport mechanism for her medical studies.

Drum House Arc
Chachamaru first appears after Tanjiro's battle with Kyogai, initially it arrives invisibly until it meows and is revealed to Tanjiro. Once the blood is tucked into the box on its back, Chachamaru hops away and becomes invisible once again to avoid detection.

Entertainment District Arc
After Tanjiro's battle with Gyutaro and Daki, Chachamaru appears swiftly to collect the blood from Tanjiro. It is given a small pat by Tanjiro before it hops away and returns to Tamayo.

Swordsmith Village Arc
Although Chachamaru doesn't collect any blood during the battle against Gyokko and Hantengu, it is seen delivering a note written by Tamayo, seemingly to inform Tanjiro that there is a possibility that Nezuko is capable of overcoming the sunlight.

Abilities and Powers

 * As a feline, it does not posses any magical powers. However, it does manage a spell of invisibility cast on it by Yushiro by meowing whenever it arrives to collect blood.

Trivia

 * They seem to like Tamayo, but find Yushiro annoying.