Though there were a number of recurring characters throughout the series, the one who appeared the most was Agatha Chumley, Higgins’ friend played by Gillian Dobb. Her character was a perfect complement to Higgins as she was English and seemed to have some admiration for him.
Apparently, Gillian actually had no professional experience prior to her role on the show. She was given the opportunity of portraying Agatha for a total of five seasons.
Tee Total T.C.
There was some apparent misdirection in terms of character progression since the producers suddenly made T.C. a drinker. He technically drank a beer in every episode of season 1, and suddenly just didn’t drink anymore with the following seasons.
This sudden habit change was pretty overlooked in the show but it didn’t get in the way of its success, obviously.
Higgins’ Full Name
Higgins, Thomas Magnum’s foil, was actually named Jonathan Quayle Higgins III. He was pretty well known to constantly ramble and have arguments between the other three main characters. Ultimately though, they were still a very close unit.
John Hillerman, the actor behind Higgins, commented on his character stating that, “Higgins in any situation thinks he’s the only sane person around while everyone else is raving mad.”
The gun that Magnum used throughout the show was actually a Government model Colt 1911 A1 .45 cal. Pistol, contrary to popular belief. During the Vietnam War, this gun was apparently the standard issue sidearm.
Thus, it made sense that Magnum would carry such a gun from his days spent in the Navy. This gun also appeared in some of Magnum’s flashbacks of his time in Vietnam.
A Fantastic Reference
Renowned director Wes Anderson has always voiced his admiration for "Magnum P.I.." He was such a fan that he even modeled the helicopter seen in his film Fantastic Mr. Fox after the Island Hoppers chopper in the show!
Anderson even shared that that helicopter was based on the character T.C. in "Magnum P.I.," that’s his helicopter. They needed a good helicopter [to model off of] and he thought that’s a memorable one. And well, nobody told them they couldn’t use it.