The Gargouille (also Garguiem, as gargoyle from a word for "throat") is a dragon from the legend of Saint Romanus of Rouen. The monster does not figure in the older account of the saint's life, being recorded for the first time in 1394.
The Tale of the Garguille
On the left bank of the Seine at Rouen were wild swamps through which rampaged a huge serpent or dragon who "devoured and destroyed people and beasts of the field". Romanus decided to hunt in this area but could only find one man to help him, a man condemned to death who had nothing to lose. They arrived in the serpent's land and Romanus drew the sign of the cross on the beast. It then lay down at his feet and let Romanus put his stole on him as a leash, in which manner he led it into the town to be condemned to death and burned on the parvis of the cathedral (or thrown into the Seine according to other authors). This legend was the origin for the bishops' privilege (lasting until 1790) to pardon one prisoner condemned to death each year, by giving the pardoned man or woman the reliquary holding Romanus's relics in a procession.