Formless Genesis (Duskmourn: House of Horror Commander)

Kindred Sorcery Ñ Shapeshifter - Changeling (This card is every creature type.)
Create an X/X colorless Shapeshifter creature token with changeling and deathtouch, where X is the number of land cards in your graveyard.
Retrace (You may cast this card from your graveyard by discarding a land card in addition to paying its other costs.)