Three sisters

The Graeae (pronounced Greh-eh) were three witches that shared a single eye among themselves. They lived in a skull cave in Tamir and lured people in their cauldron to be cooked. Rosella took their eye and they offered her a Scarab in order to return it to them.

Real world
The Graeae (meaning 'Old Women') were three sisters in Greek mythology. Perseus took their eye and tooth in order to tell him the secret of Medusa.