A lost child that accompanies Azazel and helps out at the demon funeral home.
It is revealed in episode 9 that Jeanne d'Arc is Mugaro's mother. His birth name is El.
In episode 10, when the capital raided Jeanne's home, she ran away and hid El in a facility housing caged and deceased demons. Using one of the demons corpses, she uses the blood to disguise El, dying his original blonde hair to dark black, as well as removing his wings.