Art of Silmarillion
This is Sauron takeing his wolf shape. When he was lord of Tol-in-Gaurhoth, the Isle of Werewolves.
'Aware of a prophecy to the effect that Huan would be killed by the greatest wolf ever, Sauron himself assumed a monstrous wolf-like form and attacked him.'
But the prophecy actually applied to the still-unborn Carcharoth, and Sauron could not prevail against Huan. Eventually, Huan had Sauron by the throat. Lúthien gave Sauron two options: either surrender to her the magical control he had established over Tol-in-Gaurhoth, or have his body destroyed so that his naked ghost would have to endure the scorn of Morgoth. Sauron yielded, and Huan let him go. Lúthien destroyed the tower and rescued Beren from the dungeons.
ink and pencil on the paper
Comments are welcome
(......sorry but I just love Sauron so much XD )