Abbaton occupies an important place in Coptic angelology as the angel of death. Two texts in particular give us details of him: a homily attributed to Timothy I of Alexandria, Enthronement of Abbaton, and the Apocalypse of Bartholomew. (See Apocryphal Liturature) 
According to the first text, the angel was originally called Muriel, and was given the task by God of collecting the earth used to form Adam. The angel was then nominated guardian. Everyone, both incarnate and bodiless beings, feared him, but by his prayers he obtained from God the promise that men who venerated him during their lifetime might be saved. An important role is also reserved for Abbaton on the day of the Last Judgment, as he will take the souls to the Josephat Valley.
According to the second text, he was present in the tomb of Christ at the moment of the Resurrection.

Müller, C. D. G. Die Engellehre der koptischen Kirche, pp. 273-76. Wiesbaden, 1959.