Jack the Giant Killer

Within the surviving tale cycle Jack is presented as a young Cornish farmer's son who rises to prominence by confronting giants during the legendary reign of King Arthur. He becomes attached to princely and courtly retinues (servant to Arthur's son, later a member of the Round Table) after proving himself as a giant-slayer, acquiring wealth and marriage into nobility. The stories graft a popular local hero role onto Arthurian cosmography rather than presenting Jack as a primordial or divine origin figure.

The narrative tradition emphasizes Jack's actions and his accoutrements rather than a fixed physical portrait. He is a young, physically capable commoner who acquires notable items in the tales: a sword (described as a magic sword in summaries), shoes of swiftness, a cloak of invisibility, and a cap of knowledge; a belt appears in some versions as a commemorative/important object associated with his exploits. Giants in the cycle vary from single enormous individuals (e.g., Cormoran, glossed as 'The Giant of the Sea' in Cornish) to specific multi-headed antagonists (examples include a two-headed Welsh giant and a three-headed giant in separate episodes), and are depicted as monstrous, often man- or livestock-eating beings.

Jack's effective 'powers' are his cunning, physical strength, and the narrative magic of his acquired items (the cap of knowledge, cloak of invisibility, shoes of swiftness, and a magic sword in the summaries) which enable stealth, speed, special insight, and combat advantage. His methods include trickery, ambush, traps (pit traps, manipulating drawbridges and moats), mutilation and beheading of giants, and the freeing of captives. Giants display great strength, predatory behavior (preying on people and livestock), occasional multi-headed forms, captivity-holding in enchanted castles, and in at least one episode association with sorcery and an enchanted lady whose condition is linked to a demonic figure identified with Lucifer. Sorcerers in the cycle can effect transformations (e.g., a duke's daughter turned into a white doe in the Galligantus episode), but such sorcery is specific to episodes rather than a universal trait of all giants.