They have many, many ribs that are powered by muscles that move them accross the ground, along trees, and in the water. Some are very poisonous, and others are just harmless constricters. They can reach lengths of 20ft, or shortness of 1ft. They can be anywere from the depths of the Atlantic, or to the deserts of the Sahara. They can climb, swim, slither anywere that you can imagine.
Some people think that they are slimy, cold, clammy, and extremely dangerous to humans.
They are none of them. They aren't slimy, or clammy, they are actually dry. They aren't cold either, just cold blooded. The only way that they can be dangerous to humans is if you mess with them, then they start to act defensivly and might strike a dumb human that doesn't know how to handle them. The above snake is the Anaconda, it can get up to 20ft or longer.