11. Jello and Marshmallows
Jello and marshmallows are both products made using gelatin (and a lot of sugar). Plain gelatin seems like an innocent translucent powder, but it is made by boiling down the skin, bones, and hooves of cows and pigs.
All sorts of scrap from slaughtered animals can be used, so once you get over the yuck factor, it is kind of good that very little is wasted of animals who give their lives for ours.