Illustrations from Jim Hill Media
"According to Keith Larue, in the darkest hours of World War II, the British Secret Service, led by "A Man called Intrepid" (aka William Stephenson), infiltrated agents into both enemy and neutral countries. The purpose of these agents behind enemy lines is obvious; but in neutral America, Intrepid's agents had a less obvious purpose: inspire sufficient public sympathy to enable Roosevelt to openly support Britain.
These agents included actors, astrologers, and — a children's author! Not only that, but the children's author was infiltrating Walt Disney's studios!
Roald Dahl, then a pilot injured in action with the RAF, was sent to the U.S. as an air attache. His outspoken style made him at once unpopular with his Air chiefs, and a favorite of the cocktail set. He was packed home, recruited by Stephenson, and sent back with a promotion, much to the chagrin of the Air chiefs.
In 1943, Dahl wrote "The Gremlins", a book for children about the hazards of being an RAF pilot. The Gremlins were little havoc-wreaking creatures, the anthropomorphized explanation for any mishaps experienced by pilots and their machines. If a plane experienced a hydraulic failure over the North Sea just as it was being bounced on by Nazi fighters, it was said that it was the work of the Gremlins. According to the Warner Brothers Cartoon Companion,
[The Gremlins were] mythical beasties, "the little men who aren’t there," allegedly responsible for "die-a-boll-lickal sab-o-tay-gee" in aircraft. While the Roald Dahl versions of the critters are probably best remembered — he wrote a best-selling book about them while serving in the war — variations on the characters go back to at least World War I. The critters took on a life of their own, and became part of the lore of World War II. The Disney studio attempted to make a movie out of the Dahl book, but ultimately abandoned the project. Disney tried to urge other studios against working with his characters — so of course, Robert Clampett went on to make two separate cartoons featuring Gremlins. First, he used a gremlin to battle Bugs, who, unusually, gets the worst of it in Falling Hare (1943). The title of the second cartoon was changed from Gremlins from the Kremlin to the somewhat less effective Russian Rhapsody (1944) before being released.
Gremlins weren't quite Dahl's invention though: the name gremlin was first coined during the 1920's. RAF insider jokes blamed gremlins for all the technical malfunctions in airplanes. Douglas Bader tells of a German Lager-Offizier nicknamed "Gremlin George" in early 1942. Gremlin jokes were widely used by the RAF during the World War II and so got into popular culture as well.
The book came to the attention of Walt Disney, who planned to make a cartoon film version. In the process, one small edition of a cartoon book was printed, featuring somewhat Mickey Mouse–ish Gremlins. These certainly looked much milder than some more recent portrayals of their species, and probably much milder than Dahl's idea of them. At any rate, the film was never made, some say because of the difficult task of making loveable creatures who exist solely to destroy Allied airplanes.(Disney actively tried to stop others from making Gremlin cartoons, however.)"