I tried so hard to find a viable list of Mecha'thun Hunter and this is the best i came up with.
Hunter got the perfect tutor for the combo pieces : Ursatron that draws Galvanizer and Mecha'thun and even Zilliax. It also got a good amount of draw via Masters call that can tutor the mechs or beasts, flare and Starving Buzzard in combo with lynxes or unleash the hounds. this combo works really well and it isnt as inconsistent as you think.
I chose to play Thlanos becouse hes cheap spell damage he can make the difference in some situations especially with Rapid Fire. You can replace him with Novice Engeneer or Loot Hoarder.
As you might expect you just need to play Galvanizer twice to discount mecha thun to 8 mana and then when you empty everything you play Goblin Prank into mechathun and then GG.
I chose to play 1x Unleash the beast becouse Zuljin often refills the hand with a second one and it makes it harder to get the hand empty.
It does great against aggro, i managed to win by mechathun against a token druid that played 2x Whispering woods and 4x Forest Aid. That matchup convinced me to post this deck.
I hope you find this deck fun and i am open to suggestions on how i can improve this deck