It is widely believed in wizarding circles that Sir Cadogan was one of the famous Knights of the Round Table, albeit a little-known one, and that he achieved this position through his friendship with Merlin. He has certainly been excised from all Muggle volumes of King Arthur’s story, but wizarding versions of the tales include Sir Cadogan alongside Sir Lancelot, Sir Bedivere and Sir Percivale. These tales reveal him to be hot-headed and peppery, and brave to the point of foolhardiness, but a good man in a corner.
Sir Cadogan’s most famous encounter was with the Wyvern of Wye, a dragonish creature that was terrorising the West Country. At their first encounter, the beast ate Sir Cadogan’s handsome steed, bit his wand in half and melted his sword and visor. Unable to see through the steam rising from his melting helmet, Sir Cadogan barely escaped with his life. However, rather than running away, he staggered into a nearby meadow, grabbed a small, fat pony grazing there, leapt upon it and galloped back towards the wyvern with nothing but his broken wand in his hand, prepared to meet a valiant death. The creature lowered its fearsome head to swallow Sir Cadogan and the pony whole, but the splintered and misfiring wand pierced its tongue, igniting the gassy fumes rising from its stomach and causing the wyvern to explode.
Elderly witches and wizards still use the saying ‘I’ll take Cadogan’s pony’ to mean, ‘I’ll salvage the best I can from a tricky situation.’
Sir Cadogan’s portrait, which hangs on the seventh floor of Hogwarts Castle, shows him with the pony he rode forever more (which, understandably perhaps, never much liked him) and accurately depicts his hot temper, his love of a foolhardy challenge and his determination to beat the enemy, come what may.