Kerrbirth, Cursed Ruins

As Kerrbirth, Cursed Ruins enters the battlefield,
you may pay 2 life. If you don't, it enters the battlefield tapped.
{t}: Add {b}{b}.
Creatures your opponents control get -1/-1.
At the beginning of your upkeep, tap Kerrbirth,
Cursed Ruins unless you pay 2 life.