The Reins of the Blue Proto-Drake comes from heroic Utgarde Pinnacle, the boss named Skadi the Ruthless. Skadi's loot-list on WoWHead doesn't include this mount, but the mount's page indicates that it does come from Skadi. And since we've got one, and we remember where we got it, we can confirm that heroic UP is where ya gotta be. But as we say in the movie, there are a couple other colors you can try to collect:
The Plagued Proto-Drake is the reward for completeing the normal Glory of the Raider achievement.
The Black Proto-Drake is the reward for completing the heroic Glory of the Raider achievement.
The Green Proto-Drake comes from the Sholazar Basin Oracles, a possible random reward from the Mysterious Egg.
The Red Proto-Drake comes from the heroic Glory of the Hero achievement.
The Reins of the Time-Lost Proto-Drake comes from a rare spawn in Storm Peaks that drops this mount.
The Violet Proto-Drake comes from the What A Long, Strange Trip It's Been achievement.
We've tamed a Spirit Beast and looted a proto-drake this year, our luck is probably done. If you're a squishie or a tank and need gear, come run an instance with us; mail-armor isn't going to drop for this hunter until 2010.
You are invited to download the full-sized version (74MB) of this movie here.
As always, a great big Thank You to the WoW Insider editors for allowing us to publish this movie both here and on our little blog at the same time!
Nobody covers raid Hunters like BRK. Looking for more Hunter goodness? Check out our non-raid Hunter column, Scattered Shots or the WoW Insider Directory of Hunter Guides.