Beithir

The beithir is a large snake-like creature of Scottish folklore, possibly originating from sightings of large grass snakes (Natrix natrix) or European eels (Anguilla anguilla).

The beithir was considered one of the Fuath. They were said to be sighted on summer nights when lightning strikes occurred. It was written by John Gregorson Campbell that if a snake is killed then its head must be removed and disposed away from the body. Otherwise, the two parts will come together and the snake will come back alive as a beithir.

According to Celtic mythology scholar James MacKillop the word beithir may be derived from the Norse for bear or possibly thunderbolt. Writing in the Celtic Review in 1908, folklorist E. C. Watson described the beithir as an inhabitant of mountainous caves and corries, adding that it was a "venomous and destructive creature". He considered the basis of the folktales were founded in the destructive forces of lightning and the characteristics of a serpent.

In the 1930s beithirs were reported on ground near Loch a’ Mhuillidh in Glen Strathfarrar and Sgùrr na Lapaich. A group of fishermen saw a creature about 9–10 feet (2.7–3.0 m) long coiled in a gorge near Kilmorack in 1975. It became agitated upon sighting the fishermen and swam away towards Beaufort Castle.

The creature might be a mythological elaboration of the grass snake (Natrix natrix), which can grow up to 6.5 feet (2.0 m) in length in southern Europe. Another possible source of the myth is the European eel (Anguilla anguilla), which spawn in the Atlantic Ocean and swim upstream into freshwater, and grow up to 4 feet (1.2 m).

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