DBC edit, swapped Rusted Proto Drake to a different skin of the new (10man and 25man ICC achievement) Frost Wyrms, called Frost Brood Vanquisher. This one does not exist in game yet, but was previewed by a few websites during the PTR. This may end up being the relentless or wrathful gladiator mount, but for now it is an unused skin.
Different skin of:
Icebound Frostbrood Vanquisher
Bloodbathed Frostbrood Vanquisher
Download.
I do not take requests. I learned to do this in ~15 minutes from this lovely guide in the guide subforum:
[Guide] ~sInX's Walkthrough to Mount-Swapping!