Undead Dragon Overlord

Only playable if you control a Warlock and if
there is at least one Dragon creature in a
graveyard.
Tap your Warlock and exile a Dragon creature
from a graveyard: Create a black Zombie Dragon
token with power and toughness equal to exiled
Dragon's power -1 and toughness -1. Token has
flying if exiled Dragon had flying.
"Arise, mighty one, and serve ME!"