Scabaras was created by Tumeken

Scabaras was created by Tumeken during Tumeken's Dream from an ordinary beetle. He is the desert god associated with isolation and mental tranquility, and so his followers typically isolate themselves underground to meditate in peace. As a reward for loyalty, his followers have become more insect-like in physical features as well as mentally. During the Second Age, Scabaras followers were not regarded as 'evil', and were seen as philosophers and intellectuals.

The Pharaoh Queen, Senliten, attributes this to lack of cooperation amongst factions of gods and their followers. Scabaras is said to have formed the Kalphites as well, by bleeding on scarabs. Today, Scabarites are banished from the Menaphites' society, supposedly because after the Edicts of Guthix Scabaras broke the laws by interfering in the world and even had his followers attempt to dig under the River Elid. For this, the Menaphites retaliated and even now look down upon the worship of Scabaras.
You are given this dagger after completing the Contact! quest. It is an enchanted weapon created by followers of Elidinis to especially damage Scabaras followers.Fanatical followers living alone underground throughout the Kharidian Desert, large group in ruins of Ullek (with High Priest of Scabaras)