According to the Underworld novelization, Nathaniel is well over 300 years old. He once dabbled in archaeology, and seems to have an appreciation for poetry. Similar to all other known Vampires, Nathaniel holds a strong hatred of Lycans. As a Death Dealer, he has devoted his life to driving the entire Lycan species into extinction.
Nathaniel accompanies Selene and Rigel on a hunt for Lycans, the mortal enemies of the Vampires. Initially, Nathaniel is charged with watching the exit area of the Ferenciek Square metro station, while Selene and Rigel continue to track the Lycans. One of the Lycans, Raze, suddenly senses the presence of the Vampires and begins firing on them with UV bullets. Upon hearing the gunfire, Nathaniel runs to the scene, where he finds Rigel dead and Selene chasing the smaller of the two Lycans, Trix.
Raze tosses his gun to the side and flees towards the abandoned areas of the subway. Seeing this, Nathaniel gives chase and is eventually able to corner Raze in a secluded area. Raze tosses Nathaniel to the side, then changes into his wolf form. Nathaniel hisses, but he is brutally torn apart by Raze, killing him.
Later, Selene tells the Vampire Regent Kraven that Nathaniel may still be alive, and that this is reason enough to return to the subway and hunt down Raze.
Nathaniel is mentioned in passing in Blood Enemy; when two teams of Death Dealers storm Leonid Florescu's 'country compound'; a converted monastery/church, (where the very same crypts/catacombs where Lucian and Sonja took refuge from the dawn and pursuing humans are located), Nathaniel is mentioned as one of the Death Dealer's on Kahn's team, creating a distraction, while Selene's team infiltrated the estate to eliminate the 'rabid' She-Lycan, Leyba.
- Nathaniel's name is derived from the Late Latin "Nathanael", the Greek "Nathanael", and from the Hebrew "Nethan'el", and literally means "God has given." It is a variant of "Nathan"
- Nathaniel once met the poet John Milton in London in 1645.
- He dabbled in archaeology in Egypt beside Howard Carter and Lord Carnarvon.