The Three sisters (aka three witches, three hags, weird sisters, Graeae, and sometimes Phorcides) are the three old witches that shared a single eye among themselves who live in Tamir.
Background[]
The ancients Greeks knew of three women who they called the "Graeae," or sometimes "Phorcides." These weird sisters had only one eye and one tooth to share among them, and Perseus stole both of them from the old women. They are the sisters of the gorgons and were born as old women. Their names are Enyo, Phephredo, and Dino, and they live in the far, far west, in a place where the sun never shines.[1]
They are witches of the dark variety, followers of the lefthand path who used their magical art for evil.[2]
In world of Daventry, they lived in the Skull Cave in Tamir and lured people to their cauldron to be cooked. Rosella took their eye and they offered her a Obsidian Scarab in order to return it to them. They are also described as the "hag sisters" according to KQ4.
Behind the scenes[]
These are called the Three sisters in the King's Quest Companion. In the KQ4 hintbook they are called; "The Three, One-eyed Witches".
They are based on the Graeae (meaning 'Old Women' in Greek), though never called that in the game. The Graeae were three sisters in Greek mythology that shared an eye to see and a tooth to eat. Perseus took their eye and tooth in order to tell him the secret of Medusa. Also known as the gray old women.
The term 'weird sisters' and concept also originates from Celtic mythology where they were known as the "Wyrd" sisters, roughly similar to the Norn in Norse mythology or the Morae (Three Fates) in Greek Mythology (another group of three witch like individuals).
The "three witches" in KQ4 are also closer related to the ones seen in Macbeth who are also referred to as the 'weird sisters", who lived in a cave and made prophecies. They said the famous "Double, Double Toil and Trouble. Fire burn, and cauldron bubble" verse.