The Black Maw

Counts as a Waste.
The Black Maw comes into play tapped.
When The Black Maw comes into play, tap all creatures in play. They do not untap next turn.
{t}: Add {b} to your mana pool.
All {u} producing lands gain {t} : Add {b} to your
mana pool.
From treasure island to nightmarish hellhole in
less than an hour.