King Arthur’s alias in the French romance Le Chevalier du Papegau.
Arthur adopted the name after winning a magic parrot in a tournament at the Castle Causuel, in which he championed the Lady Without Pride. The parrot was intelligent: it sang, recounted Merlin’s prophecies, and advised Arthur during his adventures. Served by a dwarf, it was kept in a golden, bejeweled cage. Arthur enjoyed several adventures under this pseudonym, and the lady Estrales declared her love for him.
Source
Le Chevalier du Papegau | Late 14th century or early 15th century