Like Clotho and Lachesis, Atropos is a being that has lived since humanity has first began. However, as his workmates likely serve a more peaceful god, Atropos is a servant of the nefarious Crimson King, selecting people who will die in sudden things, such as disasters, sickness, crime, or in accidents.
Given a large list of people to kill by the Crimson King, he cuts the thread of life the second they cease living. Being a being that lives across ages, he has a large affect on King's stories, ending such lives as Gage Creed and being active in extremely dangerous times, such as when Pennywise plauges the town of Derry.
In his novel, the lives on Earth are called "short-timers" or "Shorts", referring to their relitively short lives. Anything that exists in higher dimensions are" long-timers,", and above them, "eternals," Being a personifacation of demise, he, Clotho, and Lachesis has influnced other gods of death like Thanatos, Baron Samedi, and Kali.
At the start of the novel, Susan Day goes to the town of Derry to deliver a speech about abortion, which she supports. However, the Crimson King selected her and a large mass of her followers to be killed in a massacre. For this he chose Ed Deepneau to commit the deed, as he visits him in a attempt to drive him mad.
The death deity also makes visits to other people, including Dorrance and Ralph Roberts. Ralph, the main protaginist, begins to suffer from insomina and notice Clotho and Lachesis out on the street. He then goes to a higher plane to visit the two beings with Louis, a fellow insomniac. There, they learn their destiny.
Atropos continues to haunt Ralph, making him auras around people and death-bags and bugs around people who will die soon. Ralph also notices that Atropos wearing a friend's hat, a signal of their demise. The god they tries to kill a dog, but is stopped twice by Ralph before succeeding.
Ralph tracks Atropos down to his hideout after he stole some earrings from Louis. Ralph then cuts a deal that if he gets back the earrings, everyone in the city is spared. Although he does agree, Atropos wanrs that he isn't fully responsible for what happens, noting that he would have to make a deal with a far tougher figure: the Crimson King. Ralph then slices Atropos' scalp, but doesn't kill him.
Swearing revenge, Atropos decides to end the lifes of Ed's wife and his daughter if Ralph doesn't save his victims. However, a fully insane Ed rams a plane into the confrence center, killing hundreds of people, including Susan Day. However, his fellow grim reapers, Clotho and Lachesis, also suceed in saving Patrick Danville, who is destined to save the world.
Atropos tries on last time to end Natalie's life by running her over, but Ralph, who made a deal with the other two gods to save her life for the cost of his, dies instead. Although he isn't living, the story ends on a good note, with Ralph being able to sleep in peace, and Atropos left furious.
Atropos is a rather small figure, being roughly only three to four feet in height, having a bald head, and wearing a treachcoat, pants, and fairly large shoes.
A clever and barbaric figure, Atropos is rather mentally unwell, with his behavior switching from calm and extremely aggressive at times. He also has the power to transform into his latest hits, which he uses by taking the form of a recently killed girl.