Desert Frontier

As Desert Frontier enters the battlefield, choose a creature type.
{t}: Add {c}.
{t}: Add one mana of any color. Spend this mana
only to cast a creature spell of the chosen type or activate an ability of a creature source of the chosen
type.

"Sweet Blasphemy, Sand Mantas galore! Talk about
your prehistoric pigeons. And they're filthy animals...
they're just filthy!" —Left Hand speaking to D