Satyrs are known for their mischief and magic. Seems that this one thought this human stranger could use a bit more "ass" to his looks. Making a bit of a "donkey satyr" out of him. Of course.... the human was not for this, and displayed his displeasure at what the satyr had done. Of course, when dealing with mischief makers, it's best not to get on their bad side. So, since the human did not like being more "ass" in form, the satyr decided he had a better form in mind for him.... after all, that donkey-faun sure looked like he had fun with what was between his legs, so why not give it a try himself?