NecroLock

The deck is inspired by the awesome Naxx cards that have come out and my desire to be a necromancer. It is full of combos while keeping its consistency through good board control. This is a midrange deck with some staying power in the late game thanks to Kel'Thuzad and great board control in the early game with Nerubian Egg combos and deathrattle synergy. 

Deck goals
- Keep board control with sticky death rattle minions
- Use the deathrattles to force good trades
- Use the deathrattles to force them to trade multiple cards for a single card.
- Use Baron Rivendare and/or Kel'Thuzad to get huge value from the deathrattle minions

Individual card explanation
Minions:

Undertaker:
The only 1 drop in this deck which almost always becomes a 2/3 for one at the minimum because of the 6 2 drops with deathrattle. It is usually used to gain a 2 for 1 or trade with a more expensive turn 2 or 3 drop.

Ironbeak Owl:
This is simply used as a cheap silence which has been getting more and more vital with the Naxxramas cards. It's also useful for removing taunts for lethal or to get the advantageous trade.

Haunted Creeper:
A solid deathrattle 2 drop which acts as a mini harvest golem to help keep board control and is also a great activator for the undertaker. With Baron Rivendare it can fill up most of your board when it dies.

Loot Hoarder:
A good draw card which can get insane value with either Baron Rivendare or Kel'Thuzad. Otherwise it's an activator for the undertaker and a life tap that doesn't cost you 2 health.

Nerubian Egg:
A star in this deck. I almost never have trouble activating the egg with the 7 cards in the deck that can be used, usually void terror or Power Overwhelming (or both) are used. If Baron Rivendare is used then your getting 8/8 of stats for 2 mana. Even if you can't crack it open it will work well to counter Flamestrike and other AoE.

Harvest Golem:
Always a solid 3 drop and in the deathrattle deck it only gets better. Difficult to remove early game and helps maintain board control. If your lucky you can get a 2 for 1 with it as well.

Void Terror:
Another star in this deck. It is the perfect activator for the Nerubian egg which can leave a 3/5 and a 4/4 on the board at turn 3 (even better if you had the undertaker on turn 1). It's also great for making sure the power overwhelming buffs don't get lost. If Kel'Thuzad is out then this card becomes godly as it can absorb the stats from the cards it kills and have them appear again as if nothing happened. There is also the ability to use the to trigger the Stalagg/Feugen combo and as a bonus if you are able to drop this between Stalagg and Feugen then 2 copies of Thaddius will be summoned and you will end up with a 14/14 as well for your troubles. Expect the insta-concede after that.

Baron Rivendare:
The card which made me want to build this deck. It's odd stats of 1/7 help it stay alive and keep on pumping out value off all the deathrattle minions. It's also useful for taking our tokens such as the paladin's recruits. When used with any deathrattle it is worth it and the 4 mana cost means that often you can follow up with a turn 5 sludge belcher which becomes a very difficult wall to break through.

Sludge Belcher:
A 3/5 taunt which summons a 1/2 taunt when it dies. What more could you want except to have either (or both) the Baron or Kel'Thuzad on the board with it. It's a very difficult to remove taunt unless the opponent has silence. The 5 mana cost means it fits in perfectly behind the Baron and it adds some much needed taunt to this deck.

Feugen:
A 4/7 for 5 is already a solid card on its own and with it's deathrattle of bringing out Thaddius it can turn around and win you the game. Even if you don't draw Stalagg it is always a solid turn 5 play with 7 health being very difficult to remove and often trading as a 2 for 1. If Stalagg is on the field with it or has already been killed then the opponent will usually be trying their best to keep it alive while it keeps on swinging.

Stalagg:
Most of what was said about Feugen applies here. Stalagg though is a lot easier to remove (which is sometimes a good thing) and packs more of a punch. A great card just for its stats if you have board control or a taunt up.

Sylvanas Windrunner
An extremely good deathrattle card. If either Baron Rivendare or Kel'Thuzad are on the field when it dies it can turn the game around or seal the win. It has below average stats at 5/5 for 6 but it is still a solid body. It can be used with Power Overwhelming as a 7 mana random mind control on the turn you play her which means that it can be easier to drop onto the board with either Baron Rivendare or Kel'Thuzad. It also works very well with void terror to preserve the stats while still gaining the mind control effect. Edit: I used to run a Defender of Argus in this slot and I will put the explanation in the substitutions section.

Kel'Thuzad:
My new favourite card. This card is amazing fun to play with, it has solid stats of 6/8 for 8 which is out of the range of Big Game Hunter and still very strong. It's an below average card if played onto an empty board on your side but if there is even 1 card on your side that you can trade with it can get some amazing value. If the opponent can't deal with this card on their next turn then the will almost never be able to come back from the free trades you able to make. It also synergies with deathrattles perfectly by allowing you to activate them without fear of losing the original card. You will usually end up with a full board quickly because of your cards summoning minions when the die and then coming back at the end.

Spells:

Power Overwhelming:
A extremely useful and versatile spell in this deck, it can be used as cheap removal when used on a cheap deathrattle minion such as the Haunted Creeper. It is one of the best cards to activate the Nerubian Egg with allowing you to get 4 damage and turn the cost into an advantage. It can also allow you to kill off one of your own minions if you are in need of the deathrattle that turn. This card can combo with Kel'Thuzad but Power Overwhelming must be played BEFORE Kel'Thuzad has been summoned. The order in which the minions have been summoned doesn't matter only when Power Overwhelming has been played in relation to Kel'Thuzad. (Thanks to RyGuy182 for pointing this out to me)

Soulfire:
Soulfire is a great tempo play but can cost you the card advantage you have played but that can be made up for with the card draw from Loot Hoarder and the Life Tap hero power. It can also target the enemy hero which is very useful for racing to the win. You won't often have an empty hand so you won't be able to rely on avoiding the discard.

Hellfire:
Another multi use card in this deck. It is great for crowd control and is vital for beating decks like zoo and token decks. It can also be used for activating your own deathrattles while clearing or severly damaging the opponents board. In some situations it can also finish off the game by doing an extra 3 damage to the opponents hero.

Shadowflame:
Another great AoE card that works well with the deathrattle cards in the and can be a 5 mana Flamestrike or stronger when combined with Power Overwhelming. 

Siphon Soul:
A six cost hard removal may seem expensive to have 2 but this card's ability to heal 3 health can be the difference between life and death and also helps get through the big taunts as this deck doesn't have a very high attack power on average. Unless very necessary save this for cards that you wouldn't be able to trade into well or high cost minions such as Sunwalker or Ancient of War.

Substitutions:
I have far from a complete card collection so there are a few cards which could make this deck stronger. I apologise if any of the substitutions don't work perfectly as I don't have the cards and it is based of seeing them played against me and theory crafting. 

Bloodmage Thalnos:
A great substitution for a Loot Hoarder which is mainly used as card draw. Bloodmage Thalnos adds spell power for that extra bit of utility.

Big Game Hunter:
This can be put in to replace a Siphon Soul. Its much cheaper but is only able to hit very big minions which is usually what Siphon Soul is used for. The lack of healing however minor could be missed but the extra body can be a good replacement.

Cairne Bloodhoof:
A extremely good minion that only gets better in this deck with the deathrattle synergy. If either Baron Rivendare or Kel'Thuzad are in play when this dies then you get some insane value. It can be put in to replace Defender of Argus, Stalagg or Feugen (don't leave Stalagg or Feugen alone in the deck though).

Sylvanas Windrunner:
Another extremely good deathrattle card. Again if either Baron Rivendare or Kel'Thuzad are on the field when it dies it can turn the game around or seal the win. This card can also replace Defender of Argus, Stalagg or Feugen in the deck well. Edit: This card has now been put into the deck to replace Defender of Argus.

Hellfire &Shadowflame:
You can trade one Hellfire for a Shadowflame easily, it is mainly a matter of preference but I find the usefulness of Hellfire greater in this deck because of the ability to set of your own deathrattles and deal 3 damage to the opponents hero.

Spellbreaker:
Spellbreaker can be substituted in for Ironbeak Owl if you find you need more of a midgame presence instead of just the cheaper silence. 

Unstable Ghoul:
This is a great anti-aggro card and can be switched in for the Haunted Creeper which will minimize the damage done to your own board as there will be less 1/1 tokens. Switch this card in if you are facing a lot of zoo or aggro decks so you can get to your late game. EDIT: I switched this in for a haunted creeper to help which helped me against the hunter matchup as it give a bit more early game control and is a hard counter to unleash the hounds.

Soulfire vs Shadow Bolt:
This choice is up to whether you prefer the incredibly cheap removal from Soulfire or the consistency from Shadow Bolt. Soulfire is a great tempo play but can cost you the card advantage you have played but that can be made up for with the card draw from Loot Hoarder and the Life Tap hero power. It can also target the enemy hero which is very useful for racing to the win. You won't often have an empty hand so you won't be able to rely on avoiding the discard. Shadow Bolt is also good removal and won't cost you card advantage when its used. You can use 2 Soulfire, 2 Shadow Bolt or 1 of each depending on your preference.

Defender of Argus:
This is a very useful utility card as this deck doesn't have many taunts (only sludge belcher) and also allows for an unexpected boost to help your minions survive hit or trade up to help you keep tempo. It's also very useful for either protecting the Baron or buffing him depending on the situation (a 2/8 taunt isn't that bad). It's also a great activator for the Nerubian egg forcing them to trade into it and give you a 4/4 which will be able to attack on your turn. Edit: I used to run this card until I was able to get Sylvanas Windrunner. Edit 2: Defender was put back into to give more taunts, I took out a silence minion.

Leper Gnome
This card was added to give the deck a turn 1 play besides Undertaker and to also be able to cheaply boost the Undertaker's stats. It's also nice when you can combo it with Baron Rivendare or Kel'Thuzad for cheap and easy direct damage. Edit: I decided to put in 2 Leper Gnomes to replace the 2 Loot Hoarder so that there is more early game pressure and undertaker buffs. They are also useful for starting to wear down the opponents health and they are able to trade for 2 mana 3/2's well.

Change Log:

• -1 Shadow Bolt, +1 Soulfire to see how the cheaper removal would work in the deck
• -1 Shadow Bolt, +1 Soulfire. After success with 1 Soulfire I started using 2
• -1 Defender of Argus, +1 Sylvanas Windrunner. Yay legendary!!!
• -1 Ironbeak Owl, +1 Spellbreaker for more mid game presence
• -1 Loot Hoarder, +1 Leper Gnome for better turn 1 options and cheap undertaker boosts
• -1 Spellbreaker, +1 Defender of Argus
• -1 Loot Hoarder, +1 Leper Gnome for even more Undertaker shenanigans!
• -1Haunted Creeper, +1Unstable Ghoul to help counter the hunter matchups.

Have fun bringing back the dead!