I was looking for an animal with no hairs so there wouldn't be a confusion with fleas or e.g. cats allergy and the cat would be allergic to him/herself... (well, would be fun too, though... or its only allergic to its sibling or parents... when turning thirteen... anyways, I'm rambling ..)
And the mites are too creepy as big like this :) in the final version it hugs a teddybear full of mites.