A stylized knife used by the Incas. A tumi consists of either a crescent shaped or semi-circular blade and a handle attached to the middle of the blade (think of a spade). The blade varies from around an inch to 6 inches in diameter. The handle is often an ornate cast or carving of a figure, a priest or god, dressed in an elaborate ceremonial robes and headgear.

The tumi was used for ritual sacrifice (human? probably not, but it's up for debate), but more regularly for "surgical" use. Using a tumi, Incan doctors would carve a hole in the patient's head to let the bad blood out.