Corporal Dobson was a bit character who appears in the Season 6 M*A*S*H episode titled "The Light That Failed". The role of Corporal Dobson was played in the episode by bit actor Gary Erwin.
About Dobson[]
Corporal Dobson was a wounded soldier at the 4077th. In Post Op, Winchester, in the middle of complaining about the working conditions, gives Dobson the wrong sedative--Curare instead of Morphine--causing the young man to go into shock.
Hawkeye and B.J., in passing through O.R., catches Charles's negligent error, and manage to pull Dobson through without complications, but Winchester (whom Hawkeye refers to as "Major Disaster") isn't even grateful for the help, and was unwilling to even take the blame for giving Dobson the wrong drug.