Hearthpwn

Overview:
Abuse Witching Hour and Hadronox to create an endless wall of taunts.

Mulligan:
Mulligan for your early taunts: Tar Creeper or Annoy-o-Tron, and one of the weapon removals: preferably Gluttonous Ooze, but Acidic Swamp Ooze will work too.

Early Game:
Use turn 1 to take control of his taunts. Once they are gone, play one of yours: Tar Creeper or Annoy-o-Tron, because he will definitely play his Massive Runeblade, follow that up with one of the oozes, the Gluttonous Ooze will give you 10 armor.

Mid Game:
Continue armoring up (Ferocious Howl and Feral Rage)and playing a taunt or two a turn. Don't overextend, because you will fall victim to Brawl. Use the Branching Paths for draw unless you might die, and continue to destroy the weapons. If he gets really wide, pop a Poison Seeds. If you can stick Zilliax on either the Annoy-o-Tron (after it's lost its divine shield), or the Safeguard, that is excellent.

Late Game:
At this point, he should be topdecking, and you can play Hadronox and Naturalize it. From there, use Witching Hour to revive it, and the Carnivorous Cubes to redeploy the taunts. He will likely use his Brawls here, but they shouldn't be too much of a problem at this stage, but try and save a Witching Hour and Naturalize for a Brawl.

This is a long game, and chances are you might go to fatigue. If that is the case, use the Jade Idol to refill the deck.

Video:

My other Curse of Naxxramas decks:
Arachnid Quarter
     Anub'Rekhan (Taunt Warrior)
     Grand Widow Faerlina (Odd Warrior)
     Maexxna (Dragon Priest)

Plague Quarter
     Noth the Plaguebringer (Spell Hunter)
     Heigan the Unclean (Control Shaman)
     Loatheb (Control Priest)

Military Quarter
     Instructor Razuvious (Taunt Druid)
     Gothik the Harvester (Mill Druid)
     The Four Horsemen (Resurrect Priest)

Construct Quarter
     Patchwerk (Freeze Mage)
     Grobbulus (Odd Patron Warrior)
     Gluth (Divine Shield Paladin)
     Thaddius (Control Warlock)

Frostwyrm Lair
     Sapphiron (Fatigue Mage)
     Kel'Thuzad (Mill Rogue)