The End Boss knife is one of two personal weapons of Frank Horrigan.
The End Boss knife is a large futuristic curved knife and almost larger than a normal human. It is also one of the best melee weapons in the game, doing high damage and weighing only one pound. Though the mega power fist surpasses it in damage, the End Boss knife does not require small energy cells.
The knife is nigh impossible to obtain without an inventory editor, but it can be done by having anyone of Granite's team close or inside Horrigan's body to be able to loot it.