There's a strange combination of slider settings that I've seen occasionally. They make one's hips and legs look sort of like slightly padded versions of the copper pipe figures from those commercials for some drug to control incontinence.
Apparently it's sort of a trend in some circles; see this SLUniverse thread. Those who have their avatars set this way are referred to as "riding an invisible pony".
Having heard too many sea chanteys at Renaissance fairs, I immediately thought of this:
It wants to be filked. (It's only fair; "Donkey Riding" borrows the tune from "Highland Laddie" which got it from "If thou'lt play me fair play".)