Midrange Mech Hunter - Rise of Shadows

You don't want to start with too many higher cost cards (5+) as this is a midrange deck and you will have plenty of those for later in the game. You want to start with the early stuff you have (Shimmerfly, Ooze, Secrets, Animal Companion, Ursatron). Nine Lives is usually a mulligan because there is no synergy with using it early on as you want this card later for synergy with Necromechanic and for proccing the better deathrattles (Oblivitron, Whelp, Spider Bomb). Houndmaster Shaw is great for synergizing with Bblivitron/Whelp.