Hearthpwn

This deck is named after Onyxia, you don’t have to have it in this deck.  The deck plays the same without it, but the addition definitely strengthens the deck.

Try to have Fire Fly or Worgen Infiltrator (the Stealth helps you have another minion on your turn for your wide board) in your initial hand for turn one and/or two.  Try to have a Witchwood Apple to play on turn two.

Get Imp Master out as soon as possible (turn two if you can use a coin) to start making Imps.  The imps will help you make your board wide for Savage Roar.  You can also use Imp Master to give Cobalt Scalebane free targets.

Tar Creeper will help to keep your 1/1/s alive early on.

Druid of the Scythe can either help you buy some time with some taunt protection or help you take out early 4/4s.

Use Swipe, Starfall and Starfire to get rid of your opponent’s minions.  Swipe and Starfire can both also be used as face finishers.

Once you have a pretty good number of minions on the board you can use Soul of the Forest or Savage Roar.  Necrotic Geist is useful to have out once you have played Soul of the Forest because you get two minions for every "upgraded" minion that dies.  This works better on offense because you can attack your opponents creatures to get your minions killed.  On defense, your opponent will most likely kill Necrotic Geist first.

Violet Wurm and Onyxia are great late game beasts and creature generators.  Both of these can leave a wide board for Savage Roar (or Soul of the Forest first and then Savage Roar).

Upvote if you like the deck.