Didn't SS when I won it, but on my first run ever in MSV normal, Astral Cloud Serpent dropped from Elegon, and I won by rolling 54 against the 9 others.
Needles to say, I was quite happy and started doing my dailies for Cloud Serpent Riding, which I didn't have untill then.
Armory proof:
http://eu.battle.net/wow/en/characte...&filter=astral