As you are most aware of there is a command .mount
This command allows you, and GMs to mount yourselves and players on different mount skins, any Display ID's of NPCs will work!
Here are a few skins I found to be quite entertaining:
.mount 10318 (Goblin Racer) you sit in the back kinda on the lap of the goblin but It looks fairly sweet
.mount 9445 (Centaur) You will jut out from the side of the Centaur but it looks very funny
.mount 178 (Plainstrider) This one is unique, you actually ride it like a regular mount, on its back and holding "reins"
.mount 6086 (Zhevra) Like riding any regular Horse but its got stripes and a horn
These mount skins are only a few that i found to be very interesting, in order to find more visit your database for your server ( I used navicat) and find your NPCs (Creature_names), scroll over until you find the displayID on the NPC you wish to ride. Then Go onto your server, type .mount (NPCdisplayID)
Enjoy! ALSO NOTE VERY IMPORTANT: IF ANYONE finds out how to make any NPC ridable through items like a regular mount PLEASE post it in here so I may make my own custom mounts and can share this fun with my players.
.dismount (dismounts target)