The Ashwinder is a serpent that is created from the remains of any magical fire that is allowed to burn unchecked.
The Ashwinder is pale-grey with glowing red eyes. They rise from the embers of the dying fire and slither off into a dark corner to lay their eggs, leaving an ashy trail behind. Ashwinders only live for an hour and will collapse to dust when they have laid their eggs.
Since Ashwinders are created by magical fires, they can be found anywhere. However, if in a residence and allowed to lay their eggs, the eggs will ignite and burn the dwelling down within minutes.
"Ash" comes from the colour of itself and ashes are connected to fire. "Winder" recalls the sideway movement of some snakes like the rattler.
The Ashwinder was used to represent the worm "bloated and blind" that appeared in the retelling of 'The Fountain of Fair Fortune' in Hogwarts' pantomime while Armando Dippet was Headmaster. The creature was enlarged using an Engorgement Charm, and, as they should never have an Engorgement Charm placed upon them, exploded in a shower of hot sparks and dust.
This pantomime signaled the end of Hogwarts' pantomime tradition as it ended in the Great Hall hosting a fire caused by the Ashwinders huge eggs, which as mentioned before give off tremendous heat. It also exploded with showers of ash and ember causing further chaos. Professor Silvanus Kettleburn, who supplied this creature for the production was put on probation.