Captain Bridget "Knocko" McCarthy is a nurse who appears in the book M*A*S*H: A Novel About Three Army Doctors by Richard Hooker and then later in the 1970 MASH and then in the pilot of the M*A*S*H TV series. The character was portrayed by Tamara Horrocks in the MASH film and then by Laura Miller played the TV series pilot.
The name Bridget is only mentioned in the novel and the script for the TV pilot episode. It is not used in the film script or dialogue nor in the TV episode credits where only "Knocko" McCarthy is used.
About "Knocko" in the M*A*SH novel[]
In the novel, "Knocko" is described as may be 35 and a 5' 8" piece of solid maple. She was the "head honcho", "head coach" and leader of the operating room nurses. Knocko is frequently mentioned in the novel, more so than the Head Nurse Margaret Houlihan. She played a critical role in the O.R., assisting in the most difficult cases. A no-nonsense person, she was a nurse who had come "specifically to be a nurse." She did not tolerate lip from the doctors or from her superior, Major Margaret Houlihan.
The doctors in the MASH gave her the nickname "Knocko" because they believed she could take out any one of them in a head-on. Towards the end of the novel, when the MASH was planning for a football game, one of the doctors joked that he wanted "Knocko" in the team.
About "Knocko" in the M*A*S*H film[]
The original screenplay for the film described "Knocko" as "black, a captain in her thirties, solidly built, very strong and very competent in her job," but in the end, Tamara Horrocks was cast for the part. "Knocko" is mainly a background/side character in the film. Not much is shown of her leadership role as the second-most senior nurse and she doesn't have many lines.
She is sitting in the mess tent with Dish and Scorch when Hawkeye and Duke Forrest first arrive at the 4077th. Later she is in the O.R. assisting in an operation when Henry Blake brings in the newly-arrived Major Margaret Houlihan for introductions. Henry introduces the doctors to Margaret, and among the many nurses, "Knocko" is only one to be introduced. In a humorous scene which follows the screenplay quite closely, "Knocko" has a surgical instrument in her right hand. She hastily transfer it to her left hand and extends her right for a friendly handshake but is startled to see that Major Houlihan expects a salute. "Knocko" moves to salute but by then she had transferred the instrument back to the right hand so she ends up saluting by raising the instrument to her forehead.
"Knocko" attends the celebration party when Trapper is named the Chief Surgeon and at the end of the show she is part of the cheer leading team during the football game.
About "Knocko" in the M*A*S*H TV Series[]
"Knocko" is a mysterious character in the M*A*S*H TV "Pilot" episode. Although she is listed in the closing credits, she doesn't have any lines at all and her name is never mentioned in the dialogue.
Following the description in the novel, the script describes her as an attractive no-nonsense nurse but makes her younger at 30. There is a brief line in the script where she tells Trapper that the patient they are trying to revive is coming around. But this line is not in the episode itself so it must have been edited out.
So we can only make a best guess about which nurse she is by studying the script in detail. The script gives the positions of all the nurse characters in the first O.R. scene. Dish assists Hawkeye, Leslie Scorch assists Henry, Ginger assists Frank and "Knocko" assists Trapper. All the assignments for the other nurses check out and in each case the assisting nurse is standing beside (not across from) the doctor. So this makes it likely that the nurse standing to the left of Trapper in the first image below is "Knocko".
Later in the episode, during the party to raffle off Dish, the script states that Hawkeye dances with Dish and Trapper is dancing with "Knocko". Margaret is supposed to come in and push past Trapper and Knocko to confront Hawkeye. During the party Trapper dances only with one person, and Margaret does indeed push past the two of them so again the nurse in this second image is "Knocko". She is wearing a red Chinese gown with a Chinese word on the back.
"Knocko" is likely to be the nurse immediately to the left of Trapper (center of picture).
"Knocko" (probably) dancing with Trapper. Margaret had earlier pushed past her as stated in the script.