The Lambton Worm was a knucker that supposedly lived in a well.
Once there was a lazy knight that spent most of the time sleeping and fishing. He was the heir to Lambton Hill. One Sunday he went down to fish and all he caught was a strange worm-like creature which was a baby knucker but the knight didn't know that. The knight threw his catch into the well. In the well the creature grew and grew until he became a dangerous dragon. Soon it crawled out looking for a new home and it found one near Lambton Hill. It grew so large it could curl around the hill 3 times. It began to terrorise the neighborhood and in a short time it had eaten most of the sheep and cattle. The lord of Lambton didn't know what to do. The young knight thought he should kill the beast, so he went to ask a wise woman for advice. The woman said that if he killed the beast he had to kill the first living thing he sees or the lords of Lambton will be cursed for nine generations. He made a plan that when he killed the knucker he would blow a horn and the lord would release a hound. The knight suited up in armor covered with spikes. When the knucker tried wrapping around the knight he hurt himself. Eventually the dragon was slain and the knight blew the horn. The lord was so excited that he ran to his son. The knight couldn't bring himself to kill his father so the lords of Lambton suffered nine generations of the curse.