Snakes are covered in what?

Snakes, like other reptiles, have skin covered in scales. Snakes are entirely covered with scales or scutes of various shapes and sizes, known as snakeskin as a whole. A scale protects the body of the snake, aids it in locomotion, allows moisture to be retained within, alters surface characteristics such as roughness to aid in camouflage, and in some cases even aids in prey capture.

Source: Wikipedia