Squirrel parasites?

[swampman46]

OK guys, this is a first for me. I killed 9 squirrels this weekend, and 2 of them had what looked like a black grub sticking out of it's back. The first one had one on him, and the second one had 2. I talked to people that have been hunting over 60 years, and they've never seen this before. One guy in our hunting party wanted to clean it, but after seeing what it looked like on the meat, he threw it away. This one looked like it was just surfacing, whereas the one I killed earlier, the parasite was protruding out about a half an inch. Another in our group also had one with this on a squirrel he killed. Anyone ever see this before? This is a bit disturbing.