Birthing Hills of Kurnugia

Birthing Hills of Kurnugia enters the battlefield tapped.
{t}{p/b}:add {b}{c}.
{t}{p/b}{p/b}{x} sacrifice Birthing Hills of Kurnugia: Search your library for a creature card with converted mana cost x or less and put it onto the battlefield tapped. Activate only as a sorcery.