A knight who joined his father, Margon, in a war against the Sore Pucelle, a lady who was eventually championed by Gawaine. He was captured by the Sore Pucelle’s warriors.
The Sore Pucelle agreed to exchange him for a knight Margon had captured, but Margon betrayed the agreement by murdering the Sore Pucelle’s knight. Enraged, the Sore Pucelle launched Cargrilo to his death with a catapault.
Source
Third Continuation of Chrétien’s Perceval | Manessier, c. 1230