A brash knight who attacked Sir Guyon after he found that Guyon had captured Occasion and Furor, Pyrochles quarry.
After defeating Pyrochles, Guyon allowed him to release and fight Furor, but Furor got the upper hand and beat Pyrochles unconscious. Pyrochles was eventually healed by the evil magician Archimago and was re-united with his brother, Cymochles.
Guided by Archimago, the two brothers found Guyon unconscious and decided to steal his armor. Prince Arthur arrived during their theft, challenged them, and killed them both.
Source
The Faerie Queene | Edmund Spenser, 1570-1599