Kapaeru
He is a Kappa who has been living in the mortal realm for many years. He is in charge of gathering information regarding the location of the hunted demons. In the OVA, he has fooled persons into believing that his appearance is a disguise. He has a secret contact (whom he holds dear) that helps him get most of the clues of the cases. Both of them die at the hands of the demon that possesses Yukihime. In the manga, he tricks and betrays Enma and Yukihime. (source: wikipedia)