Assipattle and the Stoor Worm is an Orcadian folktale relating the battle between the eponymous hero and a gigantic sea serpent known as the stoor worm. The tale was preserved by 19th-century antiquarian Walter Traill Dennison, and retold by another Orcadian folklorist, Ernest Marwick, in a 20th-century version that integrates Dennison's texts with tidbits from other oral storytellers.
The seventh son of a goodman, Assipattle and his family live on their father's farm, which is nestled in a valley under the hillsides of Leegarth. A lazy daydreamer, Assipattle is scorned by his older brothers and his parents but his sister, who he is greatly attached to, is more tolerant of his idle musing and slothful ways. Often neglected and usually dressed in the tattered hand-me down clothes from his brothers, his days are spent carrying out menial tasks but he would rather avoid work as much as possible. Frequently teased by his brothers, he habitually sprawls among the ashes at the fireside in the evenings, narrating tales featuring himself as a hero victorious in all battles.
Assipattle's loneliness increases when his sister leaves home to serve as a maid for Princess Gem-de-lovely, the only daughter of the king, and his sole heir. Within a short time, the country is in turmoil as the evil stoor worm has arrived in the kingdom. A gigantic vile sea serpent, it is capable of destroying entire villages; the king is advised by a sorcerer that the only way to appease the monster is by feeding it seven virgins each Saturday. The citizens are outraged as their daughters are eaten by the stoor worm and insist the king finds an alternative solution. After seeking further advice, the king is told the only way to make the monster leave is to sacrifice the Princess; he is allowed time to find someone to slay the monster before she is sacrificed. However, one of his nobles demands that if the Princess is sacrificed and the sea monster still does not leave, then the sorcerer shall be its next victim, and the king's court agree with him.
In a desperate attempt to save Princess Gem-de-lovely, who was loved by everyone except her evil step-mother, the king despatches messengers to let everyone know he will give his kingdom, the magical sword Sickersnapper that he had inherited from Odin and the princess's hand in marriage to anyone who can defeat the stoor worm. A messenger arrives at Leegarth, conveys the news to the family and Assipattle declares he will trounce the beast, drawing mocking responses from his father and brothers.