Corpse Dance

Oracle Text

Buyback 2 (You may pay an additional 2 as you cast this spell. If you do, put this card into your hand as it resolves.)

Return the top creature card of your graveyard to the battlefield. That creature gains haste until end of turn. Exile it at the beginning of the next end step.

Card Rulings

10/4/2004 Corpse Dance only exiles the card if the card is still on the battlefield at the beginning of the end step.
4/1/2008 The effect only grants Haste until the end of the current turn. If the creature somehow manages to stick around until a later turn, it will no longer have Haste.