According to Flickr member, jtolber, it is a photo of 'something' in a thigh piece he purchased at a KFC in Marshfield, Missouri...
"The store manager tried to tell me that it was nothing and was quick to grab it from my hands and throw it away. Offered me a free piece to replace it ... yeah, right ... last time I'll ever step foot in KFC ever again. Even tried to contact their corporate office to file a complaint and never get a response."Frankly, I can look at it any longer to try and figure out what it might be because I'm starting to feel sick, but you go ahead and try. He has many more photos of whatever it is in his photo set on Flickr.