Frostlands Boneyard

When Frostlands Boneyard enters the battlefield, choose a creature type.
Whenever a nonsnow creature of the chosen type
dies, exile it. Then, if Frostlands Boneyard is
tapped, untap it.
{t}: Add {c}. Frostlands Boneyard doesn't untap
during your next untap step unless you exile a
nonsnow creature card of the chosen type from
your graveyard.