Vaal Hazak, the Undeath

Flying, deathtouch
Turf War pay 10 life ( You may cast this creature
for its Turf War cost as though it had flash only if an opponent attacks you with a creature that shares a
color with this one.)
When Vaal Hazak enters the battlefield put two creatures from your graveyard onto the
battlefield. If its Turf War cost was paid, put
four creatures instead.