KrazyGlue
Smash Champion
#460 Abomasnow
Type 1- Ice
Type 2- Grass
Ability- Snow Warning: Starts a hailstorm when this pokemon enters battle
Base Stats- 90 HP / 92 ATK / 75 DEF / 92 SP.ATK / 85 SP.DEF / 60 Speed
SubSeeder
Abomasnow @ Leftovers
Snow Warning: Timid
4 ATK / 252 SP.ATK / 252 Speed
Substitute
Leech Seed
Blizzard
Focus Punch/Protect
This is arguably Abomasnow's most practical set. The frosted tree Pokemon has a few clear advantages over its SubSeeding brethren. Hail damage hits all non-Ice Pokemon, removing 6.25% of their HP per turn or otherwise nullifies the foe's Leftovers. Abomasnow also has access to a 100% accurate STAB Blizzard, hitting opposing Grass-types immune to Leech Seed for super effective damage. Focus Punch in the last slot batters Blissey, Heatran, and Tyranitar. It 2HKOes the former two, while having a good chance to OHKO the latter. Grass Knot or even Wood Hammer can also work for Water-types but you will find yourself forced to switch out more often than liked. Protect is a very viable option as well, granting you another turn of Leftovers, Hail damage, and Leech Seed recovery.
The simple EV spread allows you to outspeed most walls while giving Blizzard a big punch. Even when using Focus Punch, Timid is recommended since you don't gain any notable kills, and there's no reason to lower Abomasnow's decent defenses. A much bulkier EV spread is 252 HP / 4 SpA / 252 SpD with a Calm or Sassy nature. Many Pokemon, specifically bulky Water-types and Electric-types, will fail to break your Substitute with their only neutral hits, allowing you to freely Leech Seed and stall them out.
Choice Scarf Sweeper
Abomasnow @ Choice Scarf
Snow Warning: Hasty
140 Atk / 116 SP.ATK / 252 Speed
Blizzard
Wood Hammer
Earthquake
Hidden Power Fire
With a Choice Scarf attached, Abomasnow reaches a respectable 360 Speed. This allows it to outspeed Gengar, tie with Choice Scarf Magnezone (assuming both of you are using Hidden Power Fire), Salamence, and many other threats. The huge surprise value and great type coverage this set packs lets it KO many of its common counters, which may spell doom for your foe. Blizzard and Wood Hammer provide powerful STAB attacks, and Earthquake hurts Steel-types, such as Heatran and Magnezone, which resist your STAB attacks. Hidden Power Fire allows you to OHKO Scizor when it comes in on Stealth Rock and is also your most powerful attack against Bronzong.
A few lesser option can go in place of Hidden Power. Focus Punch hits Blissey hard, but gets similar coverage to Earthquake. Grass Knot and Energy Ball can hit some bulky Water-types harder than Wood Hammer, and without the 30% recoil, but otherwise Wood Hammer is usually the superior option. 116 EVs in SpA guarantees you OHKO Scizor with Hidden Power if it comes in on Stealth Rock after Hail damage. Your Speed is maxed and the rest of the EVs are put into your attack to power Wood Hammer.
This set can be used well on a more offensive Hail team, functioning as a revenge killer.
Swords Dance Sweeper
Abomasnow @ Life Orb/Leftovers
Snow Warning: Adamant
4 HP / 252 ATK / 252 Speed
Swords Dance
Ice Shard
Wood Hammer / Seed Bomb
Earthquake
Although his Attack isn't very impressive and his Speed is rather lackluster, Swords Dance and Ice Shard make up for it. After a Swords Dance, Abomasnow reaches an impressive 808 Attack stat when holding a Life Orb. Ice Shard compensates for the low 219 Speed stat by getting kills on faster sweepers such as Salamence, Flygon, offensive Zapdos, and 2HKOing Azelf and Rotom-H to name a few. Ice Punch is more powerful, but leaves you open to just about any faster Pokemon. In addition to STAB, Wood Hammer allows you to OHKO Hippowdon, Suicune, and all other physical walls that are weak to it. However, the recoil damage from killing such walls will be devastating to your sweep, which is why Seed Bomb can be used. As long as you have Life Orb, you will still get the KOs you need to. Earthquake is your way to get rid of Steel and Fire-types, but since most of them are faster than you, it is best to use this on the switch in to OHKO Heatran, Infernape, and Lucario while also 2HKOing Scizor who loves to switch in.
Your Attack should always be maxed to make the most of it. By maxing Speed you outpace minimum Speed Suicune and Milotic so you get hit them a STAB Grass attack before they can retaliate. If you'd like, you can put some Speed EVs into HP, but any Fire or Fighting attack will probably kill you regardless. If Life Orb damages is off putting to you, Leftovers is a decent alternative.
Choice Band Sweeper
Abomasnow @ Choice Band
Snow Warning: Adamant/Jolly
4 HP / 252 ATK / 252 Speed
Ice Shard / Ice Punch
Wood Hammer / Seed Bomb
Earthquake
Focus Punch
The Choice Band wielding Yeti. He was cursed with rather middling offensive stats with which to make use of his wide attacking movepool, so slapping a boosting item on him helps. You have your standard physical STAB attacks. Ice Shard for priority or Ice Punch for power. Wood Hammer for power or Seed Bomb for no recoil. Earthquake provides great coverage, and Focus Punch is used mainly for lack of a better option. It does however, OHKO Blissey and Heatran who may come in to take a Blizzard. There's little to outspeed between 219 Speed, Adamant, and 240 Speed, Jolly. For this reason it is usually better to max your attack.
This set requires prediction to pay off.
Choice Specs Sweeper
Abomasnow @ Choice Specs
Snow Warning: Modest/Mild
4 ATK / 252 SP.ATK / 252 Speed
Blizzard
Grass Knot / Energy Ball
Hidden Power Fire
Focus Punch
With a Choice Specs, Blizzard becomes extremely powerful despite Abomasnow's only modest Special Attacking stat. Grass Knot hits more Water-types harder, but Energy Ball is more reliable against an unknown switch in. Hidden Power Fire allows you to OHKO Scizor and Forretress, and hurt Steel-types not named Heatran. Focus Punch is still recommended for the last slot to still hit Blissey, Snorlax, and Heatran although it won't OHKO any of them. A Mild nature gives a slight boost to Focus Punch which is why it can be used to hurt the aforementioned Pokemon.
Extra Options
Seed Bomb can replace Wood Hammer on any physical Abomasnow if you don't like the recoil, while Energy Ball can replace Grass Knot to hit lighter Pokemon. Avalanche can also replace Ice Punch since Abomasnow is relatively slow. Grass Whistle is all Abomasnow has in the way of status inducers outside of Toxic of course, but it has poor accuracy. Rock Slide is a bit too weak to warrant a moveslot, but it is useful against Moltres, Charizard, and Articuno. Although Abomasnow has Focus Blast, it won't do much damage to Blissey. Abomasnow has access to Light Screen, Safeguard, and Mist but bulkier Pokemon will certainly make better use of them.
EVs
You should always max your attacking stat when using an offensive set. Simply max Speed afterwards, which also allows you to Leech Seed more Pokemon. 84 SpA EVs lets you always 2HKO Skarmory, but between Stealth Rock, Hail damage negating Leftovers, and Leech Seed you shouldn't have too much trouble with it.
252 HP / 4 SpA / 252 SpD has been mentioned for the SubSeeder. It allows you to counter walls that can only hit you neutrally and usually stall them out with Leech Seed.
Troublesome Pokemon
Scizor resists both STAB moves and can destroy Abomasnow with Bullet Punch before he can make a move. He also packs U-turn to ruin the SubSeeding strategy. Bronzong and Forretress both work decently with Gyro Ball, but their lack of Speed makes them targets for SubSeeding. Metagross doesn't take much damage from Earthquake and can easily OHKO with Meteor Mash. Bullet Punch also does massive damage, and helps to avoid the annoyance of SubSeeding. Jirachi shrugs off Earthquake too, and can U-turn or simply wear down Abomasnow with Zen Headbutt or Psychic. Tyranitar despises being hit by Wood Hammer, but can switch in easily on Blizzard (thanks to the Special Defense boost he receives from sandstorm), and negate its perfect accuracy with Sand Stream—Tyranitar can then hit back with a super effective Stone Edge.
Fire-types are a big problem if you don't have Earthquake and even then, Moltres and Charizard will survive Blizzards to easily OHKO.
Stone Edge Gyarados is a good choice as its high Special Defense can sponge both STAB attacks quite well. He also has the option of using Taunt to avoid Leech Seed.
Weavile greatly fears Focus Punch and takes considerable damage from Wood Hammer, but is immune to the effects of Snow Warning and can outspeed and KO with Brick Break.