The icon or the Sim itself ?
Could you post a picture ? To do so, change to window mode and press Print Screen to take a pic.
Paste that into Paint and save it. Then upload the picture to a third party image sharing site like imageshack and then post the link here.
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Is the sim just wearing the Llamacorn outfit? I have not had the pleasure of seeing the llamacorn outfit in my own game, but the "winged pony" suspiciously sounds like that might be the case for your sim. Is the sim in the Athletic career, at least level 3? The llamacorn mascot outfit unlocks at that level. Just change his clothes and he won't be a winged pony any more.