First Appearance: Amazing Adventures #1 (June 1961).
Appearances: Too many others to list.
Years Active: ?-present.
Doctor Druid's origin has been described: originally he was Anthony Ludgate, a psychiatrist who devoted himself into researching the occult and who was summoned to help an ailing Tibetan lama. The lama, who was the Ancient One, put Ludgate through a series of tests and then, after Ludgate passed the the tests, the Ancient One "opened Druid's mind to its hidden powers and taught him the mastery of certain mystic arts." (This, for the purpose of seeing whether he, the Ancient One, would be able to do the same thing with Doctor Strange.)
Exactly when this happened, however, has never been set in stone (for all the obvious reasons). Marvel Universe #4-7 showed Doctor Druid in action at some time before the Silver Age, perhaps during the 1950s, fighting Gorgilla and various Deviants alongside of Ulysses Bloodstone, Makkari, and Zawadi as a member of the Monster Hunters. Given that Druid seemed, even in that adventure, middle-aged, and that his powers could easily have prolonged his life, I think it at least possible that he was active during the Golden Age and afterwards.
Ludgate, as "Doctor Druid," used his powers to fight against evil. Besides Gorgilla, he also encountered (in Ronald Byrd's words)
Krogg, an extradimensional researcher (with the tried and true haunted house trap), Zemu, an alien who was posing as a sorcerer running for public office, and the Aquaticans, a race of aquatic humanoids that were obviously NOT the Atlanteans or any other race that I can recall seeing before.Druid went on to become a member of the Avengers and then to lead his own group. His current status is, of course, deceased; he grew corrupted due to weakness and was killed.
Thanks to Ronald Byrd's research, I can now provide still more information on Dr. Druid. He is the descendant of the 12th century magician Amergin and is the reincarnation of a 6th century English noblewoman in love with a Celtic alchemist. In earlier years (before Fantastic Four #1) Dr. Druid worked for the U.S. government as a consultant and operative in "extranormal investigations;" he was known in this period as the "Midnight Eye." Per Secret Defenders #18 Druid also used, at various points in the past, the aliases "Anthony Droom" and "Guntag Borghelm."
Note: The aliases are notable. In Doctor Druid's original appearances in Amazing Adventures #1-6 (June-November 1961) Weird Wonder Tales he was called "Doctor Droom;" when he was brought back later, in Weird Wonder Tales, his name was changed to "Doctor Druid," so as to avoid any confusion with Doctor Doom. "Guntag Borghelm" was a variant name for the "astro-pyscist" (whose name usually was "Guntag Barghelt") who granted young Mickey Moran the power to say the word "Kimota" and turn into Marvelman, the Mightiest Man in the Universe. When Alan Moore began a new version of Marvelman and retold Marvelman's history, he made Barghelt's last name Borghelm. Unfortunately, when Alan Moore's take on Marvelman was reprinted in the States, the name of the hero was changed, under pressure from Marvel Comics, Inc., to "Miracleman," which may be the name by which some of you know the character. I realise that there's no chance that the Marvelman Family will ever be brought into the Marvel Universe, but this is a possible entry point for them, and I for one am overjoyed about it. Michael Norwitz corrected my initial errors here and pointed out that there is a Miracleman in the Marvel Universe, and that he appeared in Moore's Captain Britain series. Ronald Byrd, ever-sharp, noted that the Miracleman who appeared in Captain Britain was from an alternate Earth.