Durendal

The Durendal is a Whip crafted from 12 Hallowed Bars at a Hardmode anvil. If the whip continuously strikes an enemy, its attack speed will noticeably increase for a short time. This bonus will continue to occur even if the player switches to another whip or melee weapon.

Trivia

 * This item's name is in reference to a real sword of the same name,, that is stuck in a cliff side in Rocamadour.