I enjoy the mounts in this game with the exception that for all the races the mounts are simply scaled to fit.
Now realistically you should see a Lalafell riding Sleipnir and laugh. It would be a tiny body holding on for dear life on top of a giant horse.

So my idea is this: A mount that changes with class scaling.
Moogle Boots.

As a Lala, they'd have a moogle per boot carrying them with a smile on their face.
As any of the mid-range classes, you'd have 2 moogles per boot with a passive face.
As Roegadyn, you'd have 3 per boot with a strained/sweating/maybe angry face.

They'd be a flying mount and would offer a new take on the mount system.

p.s. I can see how some people might not get the joke and see it as Moogle mistreatment so maybe instead of a whistle gesture to call them you flick a coin in the air? At least it leads to the allusion that they're getting paid.