Elder Dag'eth was one of the leaders of the Zamorakian Dagon'hai in the early Fifth Age. He was presumably killed when the Dagon'hai were forced to flee Varrock following the burning of the first Wizards' Tower in the Year 70.
Dag'eth was one of a group of elders that lead the Dagon'hai for many years prior to the burning of the Wizards' Tower. Despite the role of the Zamorakians in the God Wars, they had been tolerated in society for some time. This had allowed the Dagon'hai to establish themselves in Varrock with little conflict.
Despite the apparently calm situation, beneath the surface a silent war was being waged between the Church of Saradomin and the Dagon'hai. Dag'eth was one of the war's orchestrators, ensuring that his people were constantly on the move. At some point he promoted Sin'keth Magis to the rank of Hyeraph, a decision that would eventually lead to his promotion to leader.
When the Wizards' Tower was burned, the Dagon'hai were discovered and forced to leave Varrock. Most were killed in the subsequent battle, but a small number managed to escape. Dag'eth remained behind, along with a number of other defenders such as Elder La'nou and Elder Kree'nag, the group's two other leaders.
Dag'eth is believed to have been killed while he let his comrades escaped, although he may have survived and later been executed. Sin'keth would later go on to lead in his absence.