I found out about this little worm (picture here
http://www.alaska-in-pictures.com/data/m...s_1666.jpg ) that actually lives in glaciers! So far they have been found in places like Alaska and Canada. So far no word on if any live in Greenland or not.
Just make this worm bigger and give it teeth and you've got the Penumbra worm! Considering that worms, of another species, have been found living on Antarctica, I'm positive worms live in Greenland as well. The only places I'm not sure if worms live are in the air and in deserts.