Marbas

In demonology, Marbas or Barbas 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.

The name Barbas also comes from the Latin "barba", beard, hellebore (a plant used in witchcraft, especially to invoke demons), and also a male name.

...
Wikipedia