Very Vulnerable, and Incredibly Creepy
Like most caterpillars, the Puss Moth Caterpillar is a very squishy, very vulnerable creature. Because of this it has to resort to some kind of self defense in order to keep itself alive. Rather than have any offensive capabilities, it instead uses the tactic of mimicry to scare off possible predators. Its face, as seen in the photo, is made to mimic some kind of larger creature, specifically one with bones in its face, as those are more likely to be scary than a caterpillar with no bones.
The Puss Moth Caterpillar has a bright green body, and one white spot on each separate portions of its body. The two black dots on its face are meant to mimc eyes. Then, its actual face, is in the center of what looks to other creatures as a gigantic mouth hung open. It may be a little hard to see, but if you squint your eyes, you can make out how it could look like a scary creature to other bugs and animals. On top of it just looking creepy, it acts like something from a horror movie. If you touch it, it will immediately turn around and stare at you. Touch it in a different spot, and it will stare right back at you again. No matter where you are, it will detect where your eyes are and turn around and stare directly at you. If this isn't enough to scare you, or any predator away, then through the two horns on its back, it will spray a mist of formic acid, causing extreme irritation to anyone or anything that gets in the mist.