Yamawaro

A hell creature commanded by the new Hell Girl in season 3 who takes on the look of a young boy though he can also become a yellow/green straw doll. In human form he calls himself by the name of Huang . Often quiet and having a gentle demeanor not much is known about him. He follows Kikuri on their assignments in the real world refering to her as Hime. His name is derived from the same name given to a legendary mountaindwelling creature in Kysh from Gazu Hyakki Yak an illustrated book on Japanese folklore demons. In Jigoku Shoujo Mitsuganae he was used as an experiment for this doctor that tried to make a medicine to make people young again. Then he was filled with a fungus. from Wikipedia