WoWDB

To earn this achievement:

1. Pick up the quest You're a Mean One... (A)/(H). Although it is a group quest, you do not need to be in a group. (Makes it easier, though.)
2. Get to Hillsbrad Foothills. How you do accomplish this step is up to you.
3. The The Abominable Greench's cave is in the southeast corner of the Ruins of Alterac sub-zone.
4. Help kill the yeti or fly above and wait for him to die.
5. Loot one of the sparkling presents.
6. Speak to Metzen the Reindeer.
7. Get back to Ironforge / Orgrimmar.
8. Turn in quest. Receive achievement.

BONUS

1. Pick up the next quest in the series, A Smokywood Pastures' Thank You! (A)/(H).
2. Turn it in to your faction's Greatfather Winter. Receive achievement  Simply Abominable.