Yn, the Scheming Cavern

{t}: Add {w/b} or {c} to your mana pool.
{1}{p/b}{p/b}{p/w}{p/w}: Put a 4/4 black and white Golem Horror Enchantment Creature token with menace onto the battlefield.
Indestructible
"You may challenge me if you wish. You will accomplish nothing, for I am eternal."