There are a lot of ways to get on this list: be super poisonous, be super scary or just be nasty looking. But the Burmese python does it the old-fashioned way — it's just really, really big. The constrictor is one of the largest snakes in the world, usually growing up to 25 ft. and some 200 lbs, but there have been pythons as long as 50 ft. and as heavy as 1,000 lbs. And the snakes put that bulk to good use — they grab their victims with sharp teeth, wrap themselves around their target and simply squeeze. After their lunch has suffocated, the pythons swallow them whole with super-stretchy jaws. Fortunately, Burmese pythons rarely attack human beings, and thanks to habitat loss in the Southeast Asian jungle, the snakes are actually now a threatened species. So they should be more afraid of you — though if you meet one in a dark corner of the rainforest, somehow I doubt that'll be the case.