Almadiel
Almadiel: When this demon manifests, he takes the form of a monstrous serpent with a human head. He is bound to the hours of the night and he despises the day. He will only manifest when darkness has blanketed the land. He serves the wandering duke Buriel, and his name and seal appear in the second book of the Lesser Key of Solomon,
known as the Ars Theurgia. Almadiel is hated by all other spirits, save for the others of his hierarchy. Within his own evil hierarchy, he commands a total of eight hundred and eighty lesser spirits.
SOURCE:
The Dictionary of Demons written by Michelle Belanger