Latest Appearances:
Nightmare mini-series #1-4,  Dr. Strange Sorcerer Supreme #79, Captain America vol. 3, #8-10

Profile:
Strange's oldest and most persistent foe.  Nightmare rules the Dream Dimension, where the dreams of mortals become the vehicles of his malevolence.   Many times Dr. Strange has had to enter his chaotic kingdom to battle for the lives and sanity of others.   Normally Nightmare's powers cannot extend into the Waking World, but he has found nefarious ways to affect and attack our "reality".  He once entrapped the cosmic entity Eternity in a dream state, thus warping reality and causing the "end of the world".