Barbas (or Marbas) is a demon described in the Ars Goetia. He is described as the Great President of Hell governing thirty-six legions of demons. He answers truly on hidden or secret things, causes and heals diseases, teaches mechanical arts, and changes men into other shapes. He is depicted as a great lion that, under the conjurer's request, changes shape into a man.
An incubus (nominal form constructed from the Latin verb, incubo, incubare, or "to lie upon") is a demon in male form who lies upon women, in order to have sexual intercourse with them. An incubus may pursue sexual relations with a woman in order to father a child, as in the legend of Merlin. The first known incubus was Lilu, mentioned in Akkadian documents of 2400 BC | by Russian artist Konstantin Makovskiy
DECARABIA He is a demon and, according to The Lesser Key of Solomon, a Great Marquis of Hell, although he has no title in the hellish hierarchy given by Pseudomonarchia Daemonum. He has thirty legions of demons under his command. Decarabia knows the virtues of all herbs and precious stones, and can change into all birds and sing and fly like them before the conjurer. He is depicted as appearing as a pentagram star, changing into a man under the conjurer’s request.