One of the several Welsh "saints", connected to Arthur in his Life.
As he was travelling to Somerset from Wales, the altar fell into the sea, so Carannog came to Arthur to ask if it had been found. It floated to Arthurís realm in Dindraithof (the Welsh name for Dunster).
Arthur already had it in his possession, promising to return it to Carannog if Carannog could drive away a serpent that was terrorizing Arthurís land in Carrum (Ker Moor). Undaunted by this mammoth task, Carannog placed his stole around the serpent's neck and pacified it. Having then ordered it to do no more harm, the saint let go again.
In the meantime, Arthur had tried to use the altar as a table, but anything he placed on top of it was thrown off. Arthur returned the altar to Carannog, at the same time awarding Carrum to the saint. Carannog then resumed his journeys and founded the town of Carrof.
Carannog then built a chapel for the altar, which, so John Leland (chaplain to King Henry VIII) tells us, was at Carhampton, a short distance from Blue Anchor Bay, between Minehead and Watchet, though the church there today is not dedicated to the saint.