This is a live goat fluke. I was using raw goat's milk from a farm. Typically I would ferment the milk into yogurt, and sometimes strain and keep the whey. I put a jar of whey in the garage fridge and didn't check on it until months later. When I finally did, this particularly jar was filled with three adult parasites, some black "scum", and loads of eggs swimming in the water. This is the life fluke after I emptied it onto a paper towel.