The Overseer is a parasitic organism residing in the Abyssal Nexus that serves to inform the player about the area. Behind it is the Font of Consumption, where players can place unsired in exchange for valuable items, such as abyssal daggers and pieces of the abyssal bludgeon.
It explains the Abyssal Nexus contains Abyssal Sires, who are "engineers of this [Abyss] living pocket universe", and were imprisoned in the Abyss as well. As centuries passed on food began to deplete, and they were forced to construct the Nexus, using it to absorb demon flesh and weaving it into the wall's fabric, where they currently remain in deep stasis.
It has resided in the Abyss for a long time, and stated it had participated in the God Wars, when Zamorak sought reinforcements from any reachable plane. The Overseer and its party had reached the abyss, seeking additional allies. However, the Overseer had found itself unable to escape, leaving him out of the God Wars.When the player speaks to it, he requests the player bring him the three parts of the Abyssal Sire (axon, spine, and claw), so that it may create a weapon for the player. When creating the first bludgeon, players can give the Overseer the body parts; he will hold them until all parts are obtained. After collecting all three parts, the Overseer will create the bludgeon and present it to the player. It will then claim that by creating the bludgeon, it gained the power needed to escape the Abyss, and that the bludgeon is a "living weapon whose power is rivalled by few weapons in Gielinor". Honour bound by their agreement, the Overseer leaves an ancient tome to allow the player to create more Abyssal bludgeons before teleporting away to an unknown location.