Hearthpwn

I saw other decks on here, but I did not have the resources to make them. 

The mulligan is to play the Murloc Tidecaller on turn 1. Every round after that, protect it all costs. Use flametongue and freeze to kill taunts and enemies while you focus on the Lich King. I was able to buff Murloc Tidecaller early on with Windfury, and I looked for buff giving murlocs with Primalfin Lookout I used bloodlust on either 5 or six. Beat the Lich King on turn six.

It might take you a few tries, but it worked for me.