Fool Your Friends!

The Chilean Four-eyed frog has a pair of eyespot marks on its rear end. They are really big poisonous glands with spots on them, but it looks like eyes when you look at them from behind. The spots usually are covered by the thighs when the frog is sitting, but when it feels any threat, it will expose the "fake eye spots" and cause them to swell up a bit, which (hopefully for the frog) will fool the predator into thinking that he is bigger and meaner than he really is!