A dragon is a creature of immense size, similar in appearance to a lizard.

It's skin is usually riddled with scales, it has wings, claws and fangs (sometimes horns). When The Dark Tower Series begins, dragons have long since been extinct. The only appearances of a dragon in Roland Deschain's world is the one King Roland faced in The Eyes of the Dragon and the one that Tim Ross encountered on his way to find Maerlyn in The Wind Through the Keyhole.