I once accidentally wiped the fluid from inside a cow's eye on my forehead. I was dissecting an eye and instinctively went to scratch an itch without thinking. I then forgot I did it, so I had dry cow eye juice on my forehead until my next shower.
I also accidentally dropped part of a frog intestine on my driveway and picked it up with a ziploc bag. Yes, I was dissecting a bullfrog on my driveway, because I missed the frog dissection at class and my amazing teacher let me take it home with me. I took pics but idk where they are.
I've also touched some unknown scat I found in the front yard. It looked like scat from a carnivore.
I also beheaded a dead baby bird I found when I was little because I thought it seemed like a great idea.