Arctic Eldrazi

As an additional casting cost, at least one of
the mana spent must be {s}
{t}: Tap target land, it does not untap during
it's controller's next untap phase. If it is
targeted before untapping, destroy it.
{c}{s},{t}: Tap target creature, it does not untap
during it's controller's next untap phase.
"In the tundra they are unaffected to the attic
temperatures. Truly alien and truly
destructive."