Yawr, Who Yawrs

Haste, First-Strike
{x},{t}:Look at the top 5 cards of your library. If a non-land card from among them has CMC less then x, you may cast that card without paying it's mana cost.
On your upkeep, flip a coin. If you fall it correctly, Yarw, Who Yawrs deals 3 damage to any target.