Feast of Winter Veil

 

1. Scrooge

Throw a snowball at Muradin Bronzebeard during the Feast of Winter Veil.  

Muradin Bronzebeard location is 39.2, 56.1 inside Ironforge

2. 'Tis the Season

Boots : Leatherworking  

Materials :1 copper bar / 1 bolt of woolen cloth / 4 rugged leather / 1 rune tread

Clothes (Green) : Tailoring

Materials : 4 bolt of rune cloth /  1 bolt of woolen cloth / 2 green dye / 1 rune tread

Hat : Dungeon drop

You'll receive a box with 20 Graccu's Mince Meat Fruitcake after rescuing Metzen the Reindeer
 

3. Let It Snow

During the Feast of Winter Veil, use a Handful of Snowflakes on each of the race/class combinations listed below. 

Orc Death Knight

Tauren Shaman

Undead Rogue

Blood Elf Warlock

Troll Hunter

Human Warrior

Gnome Mage

Night Elf Druid

Dwarf Paladin

Draenei Priest

4. The Winter Veil Gourmet

During the Feast of Winter Veil, use your culinary expertise to produce a Gingerbread Cookie, Winter Veil Egg Nog and Hot Apple Cider. 

Total mats needed :

2x Small Egg
3x Holiday Spices
1x Sparkling Apple Cider
2x Holiday Spirits
1x Ice Cold Milk

5.  A Frosty Shake

During the Feast of Winter Veil, use your Winter Veil Disguise kit to become a snowman and then dance with another snowman in Dalaran. 

6.With a Little Helper from My Friends

Earn 50 honorable kills as a Little Helper from the Winter Wondervolt machine.  

The Winter Wondervolt machines are by the flight master in Stormwind/Orgrimmar.

7.  Fa-la-la-la-Ogri'la

Complete the Bomb Them Again! quest while mounted on a flying reindeer during the Feast of Winter Veil.

Okay, for those of you new to this achievement, and want to get it as quickly as possible, here are the steps.

1) Make sure you have either Fresh Holly from /kissing Winter Revelers, or the Preserved Holly from the Winter Veil gifts.

2) Go to Ogri'la and talk to Chu'a'lor. Pick up the quest, The Crystals.

3) Fly around and look for Crystalfused Miner and Mo'arg Extractor. There are two Crystalfused Miners and one Mo'arg Extractor that walk together. Each one will yield 2-3 Apexis Shards, so killing all 3 can get you anywhere between 6-9 shards right off the bat. Why get more than the 5 required? Because you will actually need a total of 25 shards to get to the Bomb Them Again!. Others that yield a good drop rate are the Black Dragons flying above. Obsidia, Furywing, and Rivendark. They will also drop 2-3 per kill and have drop rates in the high 90th %. After that, the % rate drops, and most will only drop 1 shard. But you will eventually get the 25 required.

4) Go back to Chu'a'lor and turn in his quest.

5) Talk to Torkus to get Our Boy Wants To Be A Skyguard Ranger. When you get to the forge to get the Unstable Flask of the Beast, make sure you only get ONE flask, otherwise you waste the other 10 Apexis Shards you'll need for the next flask.

6) Return to Torkus and turn in quest, then you'll get the next quest, A Father's Duty. Fly to Bash'ir Landing and use your last 10 Apexis Shards to get Unstable Flask of the Sorcerer. Return again to Torkus and turn that quest in. Watch as his son Torkus Jr., quaffs both flasks, and goes to the Skyguard Outpost to apply. (You don't actually need to follow Torkus Jr. but the following little animation with him is kind of funny...)

7) Go to Chu'a'lor again and pick up the quest The Skyguard Outpost.

8) Talk to Sky Commander Keller, And then report to Sky Sergeant Vanderlip for the first Bombing Run. Once that is done, pick up Bomb Them Again!, and use either your Fresh Holly or Preserved Holly to turn your mount into a reindeer. Do the Bomb Them Again!, turn it back in to Sky Sergeant Vanderlip, and Voila! You have Fa-la-la-la-Ogri'la!

Edit: When I first did this many years ago, the person who lead me through had me running through this just as I wrote it down for you all (maybe that was necessary back then, I don't remember). While it may not be necessary to do the A Father's Duty part of it now, I had found it charming and a little funny. It did not tag on all that much extra time (especially if you are farming the shards from the Crystalfused Miners and Mo'arg Extractors. Besides, you can earn not only Skyguard rep here (if you are trying to get the Nether Ray mounts, you can earn Ogri'la rep as well , if you are going for exalted reps with everyone 

8.Bros. Before Ho Ho Ho's

Use Mistletoe on the Alliance "Brothers" during the Feast of Winter Veil.  

You get Mistletoe by doing a /kiss on one of the Winter Revelers at inns (reports saying that in Dalaran it works only from the Revelers in Underbelly). You might get Fresh Holly or A Handful of Snowflakes instead though. (Original comment from Ongra)

The achievement wants to you use the Mistletoe on the brothers. Simply target the brothers mentioned below and then right click on your Mistletoe.

1. Start at Goldshire. Brother Wilhelm (41.0, 65.9) is standing at the back entrance of the Blacksmith
2. Ride or fly to Stormwind's Cathedral
3. Brother Kristoff (55.2, 54.5) stands next to the fountain statue at the Cathedral Square
4. Get inside the Cathedral
5. Brother Benjamin (52.1, 47.6) is walking up and down behind the right pillars
6. Brother Joshua (49.6, 45.1) is standing at the end of the corridor next to the High Priestess
7. Brother Cassius (53.2, 45.1) is inside the right room
8. Brother Crowley (52.5, 43.5) is at the entrance of the RIGHT catacombs. That's next to the entrance of the room Brother Cassius was.
9. Take the Gryphon to Rebel Camp, Stranglethorn Vale
10. Brother Nimetz (47.2, 11.1) is at the west side of the Rebel camp
11. If the Goblins don't hate you, take the Gryphon to Booty Bay, Stranglethorn. Then take the boat to Ratchet, The Barrens. From there take the Gryphon to Theramore, Dustwallow Marsh
12. If you are Hated with the Goblins, take a gryphon to the Menethil Harbor and from there the boat will take you right to Theramore, Dustwallow Marsh. Time-wise is about the same, it's about the route you want to follow.
13. Brother Karman (67.3, 47.4) is supervising the Practicing Guards (Theramore Combat Dummies) - he's right next to the entrance of the north-east building (Foothold Citadel)