Spoiler warning: Quest and/or game spoiling details follow.
Can be used on a LIZARD head DIRECTLY EAST the teleport in deeper Banuta
to unlock a secret tunnel from Tiquanda
). You can use this tunnel to get to deeper Banuta
faster from then on. In order to reach the floor where the snakehead is located you need to destroy the Amphoras on the floor above and completed The Ape City Quest
Spoiler ends here.