Washed-up leviathan beach

You may put this land into play if a creature
with toughness 6 or more go to the graveyard.
This land come into play tapped.
{t}: Add {u} or {b} to your mana pool
{4}{b}{b}{b}{t}: Exile this land, return target
creature in a graveyard with toughness 6 or
greater into play under your control.