Fly: Iridescence

More colourful in large ("L").

OK, I'll concede that one isn't exactly cute. I'm still baffled by the cuddly spider though...
I do like their wing iridescence though: their wings are formed from two layers of transparent chitin, and the wing iridescence isn't just a random pattern of colours (the "soap bubble effect"), but is stable (the same if viewed from different angles) as the two layers actually cancel out the random iridescence, leaving only structural colouring caused by the specific shapes of the layers of transparent chitin.

I've put up a pretty aster in case you're not sold on the fly...