Elves

Priest of Titania and Gaea's Cradle scale with a board of one-mana Elves, so the deck's third turn produces mana a fair deck can't match. Survival of the Fittest spends it: every Elf is a tutor for the one the board needs, and the cards it pitches are the payoff — Squee comes back each upkeep to keep activating, and Anger gives the whole team haste from the graveyard. Wirewood Symbiote and Quirion Ranger untap Priest for a second helping the turn it lands.