I've been considering a bulky offensive Haxorus:
Item: Life Orb
Nature: Jolly / whatever boosts Defense
Ability: Mold Breaker
EVs: 252 HP, 252 DEF, 4 ATK
Moveset: Dragon Dance, Dragon Claw, Poison Jab, Earthquake
I noticed that Haxorus has brilliant attack, solid speed and decent defense, so I think a bulky offensive set would be great. All EVs are to give Haxorus enough staying power to take a few hits, so it can easily set up Dragon Dance - this compensates for the lack of attack and speed investment. After one dance, its attack and speed get incredibly high, and a life orb lets it hit even harder, although I may go with something else as this wears it down and kinda defeats the purpose of "bulky". The nature can either be Jolly (to provide more speed upon DD'ing) or whatever boosts defense (to provide more bulk). Finally, Mold Breaker lets it bypass things such as Sturdy or Levitate.
I realise it's not perfect, but it's interesting and I really wanna try it.