Kobold (コボルト, Koboruto) is a recurring demon in the series.
The kobold is a sprite of German folklore. Although usually invisible, a kobold can materialise in the form of an animal, fire, a human being, and a mundane object. The most common depictions of kobolds show them as humanlike figures the size of small children. Kobolds who live in human homes wear the clothing of peasants; those who live in mines are hunched and ugly; and kobolds who live on ships smoke pipes and wear sailor clothing.
Kobold is one of the first demons encountered by the main character, Yuzu and Atsuro. He is the first demon that allies itself with the main character.