As seen in the picture below a stag can mount a stag, which has mounted a stag, which has mounted a stag, which has, uhh you get the idea!
I am not sure if a stag can mount a lets say Sandstone drake and then have more stags mount him if so this would be a nice way to travel lots of druids lol
if that doesnt work just check the link below
http://i153.photobucket.com/albums/s222/Kegis/Lol-2.png
Best part about it you get a tauren to go on the top because you know it takes atleast 10 stags to haul his fat ass around!
I did not find this out credit goes to some guy called darkdk on my server, i think atleast. Anyways he gets credit for being on top!