Technically, they are called Costasiella kuroshimae…

… but their informal name is ‘Leaf Sheep.’ They’re one of the only animals in the world that can perform photosynthesis; they eat algae, suck out the chloroplasts, and incorporate them into their own bodies.

It’s a phenomenon known as functional kleptoplasty, if you want to get all geeky and technical about it (which I do). Basically it means they’re kind of like solar-powered slugs!