Reins of the Violet Proto-Drake

Source

Preview from the official site

Complete the What a Long, Strange Trip It's Been achievement by completing all world events. This mount moves at 100% speed while on the ground and 280% speed while in the air.

Note that data mining websites like wowhead show this mount is 310%, but the official website has released that this mount will only be 280%, like the majority of other epic flying mounts. Since April 2009, the official website now states that the mount is a 310%. Adding to the confusion, [Blizzard] representatives will not clarify the details about the speed of this mount. ^[1]

Notes

The reins item does not exist as of Patch 3.0.3, but the mount spell exists. It is likely that Mei Francis will send you an in-game mail which will contain the reins.