Mausoleum of the Dark Druid

Mausoleum of the Dark Druid enters the battlefield tapped.
{t}: Add {b} or {g}.
{1}{t}: Add {b}{g}.
{5}{b}{b}{b}{t}, Pay 8 life: Put all creature cards
from all graveyards onto the battlefield under
your control. They gain forestwalk and
swampwalk. Discard your hand.