But Perceval advanced towards the bridge, shield before his face and a prayer he’d learnt upon his lips; and clutching the axe in both his hands he strode on to the bridge to meet the two demon beasts. When the serpents saw him coming they seemed
to go wild, bristling and rearing, preparing to kill him; and I swear they plunged their claws into the sandstone slabs of the bridge. Burning and blazing in their hunger to kill, they rushed at him as fast as they could. Perceval waited till they’d reached the extent of their chains and then assailed them in a fury, brandishing the mighty axe, and struck one of them a blow that sent both its feet flying two full yards and made it recoil a lance’s length, back across the bridge. The other flung itself at him and plunged its feet into his shield: no spear, however sharp, could have smashed through with such ease. When Perceval, alert as ever, saw its feet impaled, he thrust the beast backwards with his shield and threw the strap off over his head. There was nothing foolish in this: the beast was so hampered by the shield that it couldn’t use its legs. It was a fine ploy, and Perceval, seeing the serpent struggling, wielded his axe and struck the monster between head and body, slicing clean through its neck to send the head, black and hideous, flying into the water. But the other serpent lashed its tail at Perceval, and sent him crashing down two yards behind. He leapt up, brandishing his axe, which was keen indeed, sharper than the sharpest chisel; the serpent coiled into a ball and grasped so firmly with its two hind feet that it fixed them in a marble block, and then sprang out in a lashing attack; Perceval wielded his axe in fury and hacked through its throat and into its entrails and deep into the bowel, and out of its body a red smoke belched like a blazing fire. Then he took the shield that the serpent had seized and pulled it from its claws; he slung the strap around his neck and looked in wonder at the impact of the serpent’s blow.

Gerbert's Continuation of Perceval