This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Lambton Worm (English)
The story states that the young John Lambton was a rebellious character who missed church one Sunday to go fishing in the River Wear. In many versions of the story, while walking to the river, or setting up his equipment, John receives warnings from an old man that no good can come from missing church. John Lambton does not catch anything until the church service finishes, at which point he fishes out a small eel with nine holes on each side of its salamander-like head.
John declares that he has "catched the devil" and decides to dispose of his catch by discarding it down a nearby well. Eventually, the worm grows extremely large and the well becomes poisonous. The villagers start to notice livestock going missing and discover that the fully-grown worm has emerged from the well and coiled itself around a local hill.