Seething Cavern

({t}: Add {b} or {r} to your mana pool.)
Seething Cavern enters the battlefield tapped.
When Seething Cavern enters the battlefield, reveal the top card of your library. If
it's a land card, untap Seething Cavern.
"Avoid this section of the underground at all costs. In that land, if you don't fight with the hordes, then
you're just fuel for the flames."