Found on Flickr, image by douglasgordon
Murphy, as she is known, is so named because of the law named in her honor.... I mean... The law that applies to her. She breaks, a lot. Its actually supposed to be Maleficent's dragon-form, but because of the problems associated with her, cast members started calling her Murphy.
Girl dragon with a boys name.
Anyway, Murphy breathes fire, moves, roars, and does all that dragon-y stuff that dragons tend to do (She keeps her sparkly hoard of gold across the Rivers of America in Pirates of the Caribbean).
But of course she can be a bit of a diva, so she randomly eats cast members and either feels sick from the black dye of their clothing, or chokes on the yellow satin jackets they wear (there is a rumor that there is one poor, rather large guy tasked with specifically performing the Heimlich on her.) During those days she does not preform.
By the way, if you want some amusement go find the various Murphy the Dragon Twitter pages. Some of the hash tags are fall on floor inducing.