Morcant's Eyes [Lorwyn Eclipsed]

At the beginning of your upkeep, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
{4}{G}{G}, Sacrifice this enchantment: Create X 2/2 black and green Elf creature tokens, where X is the number of Elf cards in your graveyard. Activate only as a sorcery.