Theodore Duchamp was the childhood friend of Gordon LaChance in The Body. He was one of the four boys in in The Body and film based on it, Stand By Me. And Alternatively, in Carrie, he is the owner of an Amoco petrol station in Chamberlain, Maine.
Teddy appears as a main character in The Body. In the closing of the novella, Gordon LaChance, notes that Teddy died in an automobile accident in Harlow, Maine in 1971 or 1972, making DuChamp approximately 23 years old at the time of his death. Due to details in The Body, it is established that DuChamp was employed by the Castle Rock Public Works Department, repairing potholes. This inconsistency can be attributed either to narrative error, or to a reinvention of DuChamp for purposes of inclusion into the Stephen King multiverse.
In the film Stand By Me, he along with his friends Chris Chambers, Gordon LaChance and Vern Tessio search for a missing dead body of a boy named Ray Browers in Castle Rock Oregon during Labor Day Weekend in 1959. He almost tried to commit suicide after stepping on the tracks while a train was coming towards him, but avoid from being struck with the help of his friends.
Teddy also makes an appearance in the novel of Carrie where he is now shown to be the owner of a gas station that Carrie White goes into, called Teddy's Amoco in Chamberlain, Maine. It is at one point implied in the novel that Teddy had died only a few days back and his son had taken over his buisness,