You guys remember Corridor Creeper? Well, Umbral Owl is worse. BUT--it's not significantly worse.

The name of this game is to fill your board with Gibberlings, then play a free 4/4 or two. How do we accomplish this? I'm glad you didn't ask: We play a lot of spells in this deck that either 1: Buff your Gibberlings while summoning more, 2: Give you more mana (or replace the mana you spent) for more spells or 3: Replace themselves with cards in your deck or cards from Discover. All this to make a huge board of little dudes and reduce the cost of our 4/4s, then end our opponent's life with a timely Roar of the Savage variety.