So I've obtained alot of the rare mounts for my collection and am working on hunting down some of the really rare ones. Onyxia has so far proved fruitless but I've been doing scouting for Poseidus every so often in the vain hope of finding it, but alas no luck.
Until right now

I flew over 2 spawns with nothing in sight and as I flew over the third NPCscan fired off. I was like meh, it's just that crappy captain on the ship, but I looked and it was Poseidus, alive and untagged! Swam down as fast as I could, tagged, killed and looted the reins to complete my set of rare spawn mounts (Poseidus, grey camel, Time Lost Proto, Aeonaxx drake). After camping on and off and doing alot of flyovers since he was announced it feels good to finally bag him (I was never going to save up the gold to buy him off the AH, far too pricey). 94/100, only 6 more to go.

EDIT: I guess since this was only 1 hour after midnight on Christmas Day I can call it a WoW Christmas gift. Thanks, Great-Father Winter
