I present you my deck, which one works really good in wild.
Mulligan is easy: choose many minions that you can (Tunnel Trogg, Sludge Slurper, Totem Golem). Sir Finley Mrrgglton it helps you to smorc (demon hunter or hunter heropower), but if he offer life tap, you should choose that, becuse this deck only weakness is card draw.
If Sir Finley Mrrgglton doesn't offer you life tap, the best best card for you is Spirit of the Frog. It helps draw many spells in the turn 3-4-5, which garantee you to kill your opponents before turn 6. Cheap spells helps remove another aggro decks and with frog, draw the rest of your spells.
If your spells not enough to finish the game, the best finishers is Cumulo-Maximus, that can smorc your opponents face. I tried Leeroy Jenkins in the beginning, but Cumulo-Maximus is way better, for example remove 5 or less health minion and leave a big 5/5 in the board.
I hope this helps to you climb faster and hit legend! :) If you have any question, please take a comment. Best of luck!