'Sergeant "Sparky" Pryor' is the unseen and unheard person on the other end of the 4077th's phone line, and serves as the 4077th's only immediate connection to the rest of the world. Usually it is Radar (and later Klinger) that calls him for trading, for information, if they need something or want some kind of fix (underhanded or otherwise) or a favor for an unusual situation.
- In "Bug Out" (Season 5), Sparky alerts Radar to a possible bug out of the 4077th.
- In "The Korean Surgeon" (Season 5), Hawkeye and B.J. are trying to sneak a North Korean surgeon in to work as an American doctor at the 4077th so they need a set of fake orders, I.D., dog tags and uniforms. They offer a Chinese gold watch in exchange. Radar tells the doctors that for that kind of incentive, Sparky would probably transfer his own mother. Sparky does deliver and the North Korean officer does start work at the 4077th, at least for a while until Margaret and Frank begin to get suspicious.
- In "The Colonel's Horse" (Season 5), Radar needs to patch an unusual long-distance call to Quapaw, Oklahoma in order to reach B.J.'s father-in-law to get some advice on how to treat Colonel Potter's sick horse. Sparky delivers, but only in exchange for a movie- Rita Hayworth's "Gilda" which Radar describes as having "no Indians, but a lot of hugging, kissing, and other violence." But the film turns out to be Ecstasy starring Hedy Lamarr, which Sparky was not in a hurry to return.
Sparky is evidently from somewhere in the South as he speaks with a thick drawl. He is good friends with Radar, and is a fan of Captain Marvel comic books.
Although Sparky is mentioned numerous times in subsequent episodes, his only appearance is in the season 1 episode Tuttle, during which Frank and Margaret are trying to find out more about Captain Tuttle (a fictitious character made up by Hawkeye and Trapper). Margaret tries to place a call to General Clayton at HQ in Seoul. Radar anticipates this and arranges with Sparky to patch the call back to the 4077th so that Hawkeye can take the call and impersonate General Clayton. In the same episode, Sparky mentions his real name, Sergeant Pryor. His rank insignia on his sleeve (three chevrons and one arc) is equivalent to the modern day Staff Sergeant, but the US Army had eliminated the rank of Staff Sergeant between 1948 and 1956). Sparky's unit is not mentioned but it is likely HQ at I Corps.