It's described by an expert as "what's left after a bird hits an airplane, goes through an engine. There are no feathers or any other kind of remains of the bird left except blood, guts."
Every time a tweety-bird goes into an Air Force jetplane's engines, the remains -- the snarge -- are sent off to the Smithsonian in Washington
Anyway, here's a video report from the Wall Street Journal on the subject of snarge, and who even knew the WSJ had video? Mine is just all made of paper.