Had some alligator tail for appetizer at a local restaurant a few months back. Not really unpalatable or vile, but as they prepared it it was very greasy and chewy, and not flavorful enough to over-ride those factors.
We went to Colorado and Arizona a couple of years ago, and when we got back I kicked myself for having forgotten to see if I could find some rattlesnake to eat.
Brain and tongue are both things I would have a very hard time eating unless on the brink of starvation. I know that's just subjective reaction, but it's my subjective reaction.