It's available as a costume reward for getting the Emperor achievement from Cyrodiil PVP. You need to be the top player on the leaderboard in your home campaign when your alliance captures all 6 keeps around the Imperial City.

ellmarie wrote: »

Oh! Holy! Well, just thinking about doing a pvp character to get ready for mayhem but probably not going to be leader anytime soon or ever. lol

Actually mayhem may be te best time to do it

Start as early as possible on one of the new campain and make as much ap as you can

Last time the campain i chose was rotating emperor. When one player would get it, he would abandon the campain, making the second player first. We would the let ad or dc recapture and make an emperor of their own before retaking the map, by the end at lest 25 new pact emperors had been crowned.
A few years ago i had mine atfter the first 18 hours of the campain, on a trial character on wich i barely changed anything
Granted it may not workout like that in the campain of your choosing but i think if you have the time, its worth a try

lol, I didn't notice the backside at the time, my girl's booty wags to quick!