Probably ate a cockenthrice that wasn’t quite cooked properly....Is that like a haggis, only better?
No, it's a creative medieval dish that was typically a whimsical creature made from two or more animals (or parts thereof) stitched together.
I would imagine that cooking it with disparate "proteins" involved, given the knowledge, technology, and implements of the day, would have left a lot of bacteria and parasites pretty much still alive and infecting.