Nincada

Evolve (At the beginning of your upkeep, you may pay {g}{g}. If you do, you may sacrifice this card, and you may search your library and/or graveyard for a card named Ninjask, and summon it to the battlefield. If you do so, then you may pay {b}{b}. If you did so, then you may search your library and/or graveyard for a card named Shedninja.)