Private Harker is an American G.I. who makes a one-time appearance in the Season 6 episode of M*A*S*H titled "Your Hit Parade". The part of Private Harker was played by Ken Michelman.
About Harker[]
Harker's rank is never mentioned. His rank is inferred from the fact that the credit lists only his name, a pattern common with G.I.s while corporals and sergeants more frequently have their ranks mentioned as well.
Harker arrives at the 4077th critically wounded. During surgery he starts hemorrhaging from a lacerated aorta. He urgently needs blood but the 4077th is out of his blood type - the rare AB-negative. Hawkeye sends Klinger to look for some more while he tries what he calls the old double reverse technique - collecting the blood he is losing, filter it, and give it back to him. But this isn't enough to last for long. Fortunately, a blood donor Sergeant Gribble is located and brought to the MASH, although he is stone drunk and has a donor of needles. After much adventure and misadventure, the camp personnel finally "persuade" Gribble to submit to a transfusion.
Some time later, Harker, who has been unconscious since arriving at the MASH, wakes up. He tells B.J. his stomach hurts and asks if he is going to die. B.J. reassures him that he will be all right.