Death of Sir Bruce Sans Pitie by Dante Rossetti

Sir Bruce Sans Pitie (also Breuse, Bruze), whose name means without mercy,  is described by Malory as the "most villainous knight living."

He is first encountered when nine of his servant knights are attacking Sir Palomides, who is rescued by Tristan. Bruce and his men retreat to a tower.

Sir Dinadan encounters a lady being held against her will by Sir Breuse, after Breuse killed her brother. Dinadin challenges Breuse, who flees immediately once wounded.

Sir Bruce is frequently mentioned in The Once and Future King as an example of exactly what Arthur is fighting against. He is known for sneak attacks, ambushes, and when defeated, he begs for mercy under the laws of chivalry.

Sir Bruce appeared in the 1980s animated series Ghostbusters, having been imprisoned by Merlin in a tapestry until modern times. 

Sir Bruce in "Ghostbusters"