Hi! My first upload here, so please bear with me. (Updated for the October season.)
As a hearthstone player since beta, I have always enjoyed rush/aggro decks to climb the ladder: zoo, face hunter, shockadin, coldlight rogue. These decks are fun because you either win fast or lose fast and as a result you spend less time on your grind up. However I've found that (with the exception of pre-naxx coldlight rogue) these decks peter out at rank 3-4. Control decks take over, now strengthened by many post-naxx defensive cards.
The purpose of this deck is to provide you with a tool to make that final push to legendary. Depending on the meta (which at the time of writing is Undertaker Hunter) it may not be the best laddering tool, so use your regular deck until you're stuck. In the September season I was able to get legendary in one, short afternoon from rank 3 where I had been stuck for the better part of a week. Getting to rank 3 I used Icegirl's Copperfield deck, which I had great fun playing.
The deck fares well vs. most control set-ups such as Priest and Warrior and is not too shabby against Zoo either. It struggles versus Undertaker Hunter as without a good Undertaker and Swipe / taunts start it's just too hard to keep up. Handlock is hard to win against as the deck has little against two 8/8 taunted giants.
Update Oct 11: I've replaced Harvest Golem for Unstable Ghoul to counter the swarm of Undertaker Hunters. The downside is that control Warrior is now slightly harder. I'm also debating the wisdom of KT as often the card just sits in your hand. Lastly, with Sludge Belcher and Defender of Argus in many decks I'm thinking of including The Black Knight.
The deck incorporates four main areas:
Deathrattle: The deck runs 10 deathrattle cards and a lucky start with Undertaker and any combination of Haunted Creeper, Loot Hoarder, and Harvest Golem can quickly spin out of control (for your opponent).
Ramp: Though minor, the inclusion of Innervate can expedite the play of Sludge Belcher (more deathrattle!) or Druid of the Claw, defending against aggro and quite the threat themselves. It can also speed up the use of the Force of Nature / Savage Roar combo by a turn or two.
Card Draw: Six cards speed up the card drawing process, giving you faster answers to problems on the board and getting you the combo faster. I went with Azure Drake as I often ran into Priests and it couples well with Swipe and Wrath. Ancient of Lore, other than drawing you two cards, can be a life-saver in aggro Hunter or Warlock match-ups. I did not include Bloodmage Thalnos as I simply do not own that card, but I'm not sure if I would add it if I did. (Though it could be switched for a Loot Hoarder or Drake).
The Combo: This deck runs two copies of Force of Nature and Savage Roar each with the aim of increasing the chances of you having the combo by turn 9. Although this increases the chance of dead cards, I find the heavy card cycle gives me plenty of other options. At times, the extra copy of Force of Nature saves the day by killing off scary aggro or a nasty taunt.
And lastly, a force in itself is Kel'Thuzad, which pairs well with most of the elements above: extra card draw through Loot Hoarder, extra mind control through Sylvanas Windrunner and taunts that won't die.
As said, I'm not an experienced Druid player but this deck was a lot of fun. With the many avenues it can pursue I truly found it a deck for all seasons in the current meta.