Hearthpwn

Hello guys! I'm FlerFlegma, Polish enthusiast of the Hearthstone hoping to score something in this game, and I present you this deck, which I was able to reach legend. 

Shortly about the deck:
Deck is of my creation, but based on some deck that created by someone after the Boomsday expansion. The deck idea is simple: spawn bombs, magnetize them, trigger them and generally go face. It is an aggro deck so it should be your playstyle. Why this deck? It is fast, efficient, allows making tricks some might not be ready for and suprisingly well deals even with Bomb Warrior (and other decks as well).

Mulligan Tactic:
Cards to keep (almost) always: Mecharoo, Whirliglider, Galvanizer
Cards that might be kept: all cards below 4 mana (except Nine Lives- it's clearly dead card in early)

Tracking - keep only when you have no early cards in your hand. Tracking is most commonly used when you have a lot mana to play it mana efficiently. Then you usually know, what you are looking for. 
Bomb Toss - extremely good card against aggro and tempo decks, when picked early, but quite ineffective against slower decks. Keep it when zoo's, rouges etc. or when no better cards are left to be picked.
Fireworks Tech - very good card at early (especially with Mecharoo), but only if you can trigger an deathrattle (otherwise it is crap). Keep it in mind doing mulligan.
Spider Bomb - Keep when you have cards to play in early, it is the cheapest card to keep or you know you play against some slower decks utilizing big minions.
Ursatron - Pretty decent keep. But it is very impressive in starting hand, when no cheaper cards are present.

Few remarks about strategy:
Fireworks Tech - use it wisely as it the only deathrattle trigger a hunter has right now. Two best targets for this are: early Mecharoo and Spider Bomb. Keep in mind, that you can play Spider Bomb on Goblin Bomb (or any other mech with deathrattle) first to trigger both deathrattles. It might be very important.

Galvanizer - it is the card I was looking for so long. It is extremaly good against any type of deck since it drasticly speeds up your game. If you have coin, you can make something like Coin + Galvanizer + twice Mecharoo! It is great improvement that allows you to get the board before aggro decks do so, and then control them. Also lowering the cost of combo Venomizer and Missile Launcher up to 2 mana with one Galvanizer is pretty sick.

Magnetizing - it is the core strategy of this deck. You try to always have some mechs on the board (if it is possible, even after some mass removals - see Mecharoo or Replicating Menace). This way you can magnetize it, which means some rush/charge damage. In most cases you do not magnetize a minion which you will not attack at the same turn. Simply because of the silence or any threat or loosing the minion before you will be able to attack. The best synergy is Venomizer and Missile Launcher. Yes, it totally wipes out the entire board leaving the mech itself every turn!

Defender of Argus - At first glance this card might look like it is not doing much, but in reality it is very good because of two reasons: your bombs are 0/2, have no attack, so giving them 1 attack makes them some sort of thread and can sacrifice to deal 2 dmg to the opponent face; and by giving them taunt you force in most cases the opponent to trade them by themselves, so it trigger its deathrattle.

Nine Lives - in most cases you use it to trigger again the spiderbomb and add a copy of it to your hand. NOTE! You can trigger only those deathrattle minions, that died under your control, so if u magnetize Spider Bomb or Replicating Menace with somethig else, they will not show as option to choose when you cast that spell. That's why you sometimes put your spidey next to mechs instead of magnetizing it. The second most commonly triggered deathrattle is just the Goblin Bomb, just to deal 2 to the face.

Update 1!
Replaced Necromechanic with Zilliax - Zilliax is very flexible as it can be magnetized to almost anything in this deck and it is the only rush and the only heal possibility. It greatly improves the odds of making combacks etc.

Update 2!
As I promised, I tested a version where one copy of Nine Lives was replaced by Mossy Horror. And it works. Deck does not seem to be any less powerful but its chances of dealing with other aggro decks highly improved.
Here is my reasoning:

Update 3!
It took me while of laddering and playing tournaments with different version to provide you this one, which is a little bit worse than previous in terms of fighting control decks, but manages to fight aggro much better.

I'll write more desc soon, just checkpoint changes I've made already.

Also, because some of you asked me to do so, I'm about to write some kind of guide how to face different archetypes. 

Deck is under process of improvement, if you have any ideas are questions, share them in the comments.

Here's proof of me playing this in legend:
Link to imgur

And here is cool guy named "Kiwiinbacon" which agreed to present a gameplay of it: