Gecko's can be pretty cool. Like a lot of lizards, they come in all shapes and sizes. I don't know enough about them to have a favorite, but I think the mossy leaf tail gecko is a particularly neat one. They're actually able to change their skin tones to match their surroundings for camoflauge and they do it quite well. Here is one looking like white moss on a branch, which is pretty convincing. Here's one actually matching the mottled texture of green moss on brown and tan bark and in my opinion, it's impressive as heck. Like a lot of animals, when their passive defenses don't work, they're more than willing to resort to a threat display, which is actually pretty convincing. I don't know about you, but if I saw that, I'd take a step back.