Two shakes of her tail and Fifine would be rid of it.

I always wondered how wheels could evolve, so far the only thing I can think of in nature that goes through a 360 degree spin is the bacterial flagellum...perhaps the wheels could be something like a hoof or something that detaches itself from the foot once it grows in a complete circle, then gets spun by muscles in the "axle." Uh...Sorry about that, this thing looks awesome though!

In several science fiction novels I've read about animals that didn't evolve wheels, but axles, and they construct wheels (or simply collect them) using specific natural ingredients. It would not be possible to create something like a wheel using evolved parts, but it would be easy to construct a strong, firm "axle" out of a finger, provided there were naturally occuring wheels (such as a uniquely shaped seed-pod or shell) that was in high abundance.

Wheels would also need tracks on which to travel, legs are better when going "off road." So the planet would also need long, flat tracks, such as those created by lava flows.