Vrock

Vrock is a dull-witted, capricious fiend that lives only to create pain and carnage. Vrock resembles a giant hybrid of humanoid and vulture, his gnarled, bestial body and broad wings stinking of offal. Vrock gobbles humanoid flesh whenever he can, stunning potential prey with an ear-splitting shriek, then swooping down to attack with beak and claw. Vrock can shake his wings, releasing clouds of toxic spores.
So much is known about Vrock because his attacks are very public, the exact opposite of every other member of his organisation - Dark Wing.
Vrock is a member of The Menagerie High Council.