Have you tried the "Search Renderosity" located at top right hand corner of web page?
I prefer using it's "Advanced Search" option to help filter to specific search locations.
Don't forget to check Rendo's Free Stuff section and use it's "search" option.
You'll be pleasantly surprised to find some wonderful freebies.

Another way is to have a winged animal (such as a bird) and turn off visibility to every part, excepts it's wings, and then pose the wings onto the human body. A lot of manual adjustments would be required to get the two figures in sync.  But I have found that a little patience and a lot of sheer bloody mindless determination can (but not always) pays off. LOL.