When I see this pokemon, the first thing is Choice Banded Iron Fist Boosted STAB Ice Hammer. (I only wish it got Hammer Arm so that it would get the iron fist boost and not lower your defenses like with close combat. But Alas.)
The second thing I think is Trick Room! It seems practically made for the thing (which makes me wonder why TR STILL hasn't gotten some kind of extender item or mon that sets it naturally. But Alas.)
Crabominable @ Choice Band
Ability: Iron Fist
EVs: 252 Atk / 252 HP/ 4 Def
Brave Nature, 0 Speed IVs
- Close Combat
- Ice Hammer
- Earthquake
- Stone Edge
Again, you're going to want a trick room setup in place before going to two, which is why you want to make yourself as slow as possible. But once you have that in place, you are going to punch holes in things. Ice/Fighting/Ground/Rock coverage with all being 100 BP and above with two of those being STAB is amazing coverage. Just as a point of insight, you're hitting 681 out of the current 802 pokemon super-effectively. Things are not going to want to switch into you. Of course... you're not going to want to switch into much, either, given its typing and mediocre bulk. Which is why we invest max HP if only to try and make ourselves as bulky as possible by maxing our highest stat.
There's not much to be said, here really. Just come and hit things really hard for a few turns, then switch out if need be. You are going to be kind of hit and run especially if you are using Close Combat more since it lowers defense, but if you can keep switching in and out and getting trick room up more than once than you can do a lot of damage with this set. Running it through the One Vs. All part of the damage calcuator shows it has the potential to essentially OHKO or 2HKO the entire metagame barring Jellicent/Slowbro/some physically minded Slowking Sets. In terms of pure, immediate power, this set is likely the best option.
However, we do have boosting potential that can't be denied. Since the OP's bulk-up set about hits the needle for what I was planning, and he also mentioned a life orb set with power-up punch, I wanted to share a gimmicky, to be sure, but fun set.
Crabominable @ Leftovers
Ability: Hyper Cutter/Iron Fist
EVs: 252 HP / 252 Attack / 4 SpDef.
Adamant/Careful/Impish Nature
- Iron Defense
- Amnesia
- Power-Up Punch
- Ice Hammer/Avalanche
Again, I know. A gimmicky set to be sure, but I'm sure it would surprise some folks. Does anything else even get the Iron Defense/Amnesia/Power-Up Punch combo? It seems like it should be fairly rare. But anyway, the goal here is to either iron defense or amnesia depending on what your opponent is, then go for the opposite boost, then start setting up with Power-Up Punches. The choice between Ice Hammer or Avalanche depends on what ability you prefer here. Hyper Cutter is good for not being bothered by intimidate. The last thing you need while setting up PUP's is a costly intimidate. In that case, you'll go with Avalanche, since given your speed, you're going to be hitting last most often and therefore you'll have yourself a 120 BP move. But if you just want to maximize your PUP power and Ice Hammer, then Iron Fist is the way to go.
Since you're ideally boosting both your defenses, maxing your HP is the best way to go with full attack investment to hit like a truck as well. If you are wanting to be a little bit tankier, though, you can go with a careful or impish nature and play with the evs some and put some more in Sp. Def or Def depending on what you are wanting to handle. Now again, I'm well aware your typing doesn't even permit a defensive set, really, but I wanted to try something a little out of the box and see if it stuck. In the end, I feel like Crabominable is limited by its speed to be very good in OU, despite its legitimate ability to OHKO large chunks of the Meta. It requires trick room to function at its best, and until GF decides to implement a trick room extender item, that style will always be kind of niche.
However, the sheer damage potential of Crabominable cannot be ignored. Its stabs are excellent with just the right amount of coverage to complement. Iron Fist provides an invaluable boost as well, especially when paired with choice band. All things as they are, I see Crabominable as a solid UU pokemon, and at the worst, RU. UU was home to a lot of slow hard-hitting mons in Gen VI, and I don't see things changing this gen, so I have high hopes for the Yeti Crab