Enchantment, 2B (3) Sacrifice a creature, Return Recurring Nightmare to its owner's hand: Return target creature card from your graveyard to play. Play this ability only any time you could play a sorcery.1 "I am confined by sleep and defined by nightmare." -Crovax
Illus. Jeff Laubenstein
You cannot return the creature which you are sacrificing. This is because you choose the target creature card at the same time the sacrifice is happening, so the sacrifice is not in the graveyard yet. [DeLaney 1998/06/10]
Because of the way the timing rules work, you can cast Recurring Nightmare and then use it before your opponent can use an instant like Disenchant on it, but only if you do so when the stack is empty just after it enters play. [D'Angelo 1999/06/01]
Standard (Type 2) tournaments (see Rule 804) have banned this card since 1999/04/01.