All monitors have long, forked tongues, sharp teeth, relatively long necks, pointed snouts, sharp claws, and non-autonomous tails. The eyes have eyelids and round pupils.
Body is usually fairly massive, with four powerful legs, each bearing five clawed toes.
The tail is thick and long and functions as a rudder, as a prehensile organ and as a weapon. It is twice as long as the body. The body is covered with various small, non-overlapping scales that form a granular pattern. Typically gray-brown with conspicuous white or yellowish markings. Can grow to six feet, but average length is four feet.