Hearthpwn

This deck has been giving me some really good results this season, getting me from rank 9 straight to rank 4.

Because of the mix of dragons and mechs, the opponent can be confused as to which tactic to employ against you, often spending needless amounts of resources to remove your mechs, thinking you will rely on them. Prove how wrong they were by dropping fat dragons on the board and running rampage over them! :-)

For the early game, look for your Mecharoo and the weapon (or any tempo minion). Use your mana and try not to float mana if you can (tempo is key with this deck).

Don't be afraid to drop a naked Spider Bot or Venomizer on the board. If the opponent removes it, enjoy the wasted resource. If not, magnetize something onto it to maximise your damage.

Hero Power often - you want to pile damage to the face whenever possible.

Bottom line: this deck is fun. it's not invincible, but it wins a lot. And fast. 
Enjoy!