Spinal Embrace

Oracle Text

Cast this spell only during combat.

Untap target creature you don't control and gain control of it. It gains haste until end of turn. At the beginning of the next end step, sacrifice it. If you do, you gain life equal to its toughness.

Card Rulings

10/4/2004 The sacrifice is mandatory. The last “if you do” only fails if for some reason you could not sacrifice.