Skieflyer is just a normal filly...
Scratch that.
Skieflyer is an odd filly. With her black coat and bright orange mane, not to mention the cat eyes...
Oh, and did I mention she has fangs?
No, she is not a bat-pony, changeling, or thestral....
Well, not completely, anyways.
Skieflyer, with her black coat, orange mane, cat eyes, fuzzy ears, fangs, and feathered wings, is half thestral...
...and half pegasus.