Let's get it out of the way now -- no, Jell-O isn't made from horses' hooves. It's made from the hides and bones of cows and pigs. And that's oh so much better, right? Actually, lots of other pretty tasty foods contain gelatin (like cream cheese and marshmallows), but it is the main ingredient in Jell-O. So, along with some water, sugar and artificial colors and flavors, you're basically eating highly processed animal parts. Yum?