Metzen the Reindeer was a neutral quest, that is only available during the Feast of Winter Veil. There were two versions of the quest, and both could be completed each year, although the locations of the quest givers in faction capitals would make it difficult for most to do so.
When you find Metzen, have the [Pouch of Reindeer Dust] in your possession so you can sprinkle some of the dust on him; this should free Metzen from his bonds of captivity.
DISASTER has struck! Metzen the Reindeer has been kidnapped!
Metzen is one of Great-father Winter's eight reindeer - and property of Smokywood Pastures. We've received not one but TWO ransom letters from groups claiming to have Metzen. With the holiday season well under way, we're strapped to the coin box here! Please - find Metzen and return him to us!
Check out the ransom letters for clues, and sprinkle this reindeer dust on him - it will free him from any of his bonds!
Please, hurry!
Progress
<name>! Did you find him? Were the notes in the satchel I gave you enough information to locate Metzen? I hate to think of that those cruel thugs might do to him... but there's no way we can afford to pay such an exorbitant ransom!
Completion
You did it! Huzzah!
Metzen flew back into Great-father Winter's stables—yes Metzen can really fly—just a little while ago! The dust worked like a charm; I knew it would. You've saved the Feast of Winter Veil as well as Smokywood Pastures from disaster. Thank you, <name>.
Listen... because of what you've done here, I want you to have this. It's something VERY special; if you have a mount, I think you'll get a kick out of it. Happy Winter Veil!
Free Metzen by clicking on him and choosing the dialog option, not by clicking on the dust.
Some time after having completed this quest, you received mail from your quest giver...
I just wanted to say once again thanks for rescuing Metzen from his kidnappers. Believe me when I say you've got a friend for life at Smokywood Pastures.
Speaking of which... Master Chef Graccu has been working on a new recipe here, and I thought you might like a little sample of what he has been whipping up! Have a wondrous Winter Veil!