Champion of the Undead

Zombie Offering (You may cast this card any time
you could cast an instant by sacrificing a zombie
permanent. If you do, the total cost to cast this card is reduced by the sacrificed permanent’s mana cost.)
When Champion of the Undead enters the battlefield, if it was cast on your turn, zombies
and skeletons you control get +2/+1 until end of
turn. If it wasn't cast on your turn, zombies and skeletons you control gain deathtouch until end
of turn.