Species: One overgrown snake which grows into a dragon-worm.
Source: The ‘Life of St Petroc I’ a text in Latin probably written in Cornwall, perhaps at Bodmin Priory.
Date: The historical Petroc probably lived in the sixth century A.D. Our text was first written prior to 1177, most likely around the mid-eleventh century, although the only complete manuscript (Paris MS. Lat. 9989) only exists in sixteenth century transcript form. The story itself may well have been known orally before it was first included in the written life (Doble, 1965: 133-4; Orme, 2000: 214-15).
Highlights: Once upon a time an evil villain died. He had a snake pit like most evil villains and after he died no-one was being fed to the snakes (awww). They ate each other until one got so big it came out and turned into a dragon. It happens.