In the Mabinogion, Bran the Blessed asks to be killed in this way. At Bricriu's [pr. BRICK-RE-OOS] feast, the "champion's portion" is given to Cu Chulainn (pr. COO COO-LAIN) after he is dared to kill Cu Roi in this manner.  A "magic girdle" "saves" a man from being killed in this way in a work by the Pearl Poet. Odin gains the knowledge of the word after the Vanir kill Mim
In the Mabinogion, Bran the Blessed asks to be killed in this way. At Bricriu's [pr. BRICK-RE-OOS] feast, the "champion's portion" is given to Cu Chulainn (pr. COO COO-LAIN) after he is dared to kill Cu Roi in this manner.  A "magic girdle" "saves" a man from being killed in this way in a work by the Pearl Poet. Odin gains the knowledge of the word after the Vanir kill Mimir in this way. This manner of death befell the mortal sibling of Stheno (pr. STENO) and Euryale after she was punished for sleeping with Poseidon in Athena's shrine. The Green Knight nearly killed Gawain in this way. Using a helmet of invisibility and a reflective shield, Perseus was able to kill Medusa, for 10 points, in what manner?
In the Mabinogion, Bran the Blessed asks to be killed in this way.
decapitation [or beheading or similar answers]