A gremlin is a folkloric mischievous creature that causes malfunctions in aircraft or other machinery. While depictions of these creatures vary, past findings present the animals to be similar to the chupacabra, with spiky backs, large strange eyes, and small clawed frames that feature sharp teeth.
Although their origin is found in myths among airmen, claiming that the gremlins were responsible for sabotaging aircraft, John W. Hazen states that "some people" derive the name from the Old English word gremian, "to vex", while Carol Rose, in her book Spirits, Fairies, Leprechauns, and Goblins: An Encyclopedia attributes the name to a combination of the name of Grimm's Fairy Tales and Fremlin Beer. Since World War II, different fantastical creatures have been referred to as gremlins, bearing varying degrees of resemblance to the originals.
The term "gremlin" denoting a mischievous creature that sabotages aircraft originates in Royal Air Force (RAF) slang in the 1920s among the British pilots stationed in Malta, the Middle East, and India, with the earliest recorded printed use being in a poem published in the journal Aeroplane in Malta on 10 April 1929. Later sources have sometimes claimed that the concept goes back to World War I, but there is no print evidence of this.
An early reference to the gremlin is in aviator Pauline Gower's 1938 novel The ATA: Women with Wings, where Scotland is described as "gremlin country", a mystical and rugged territory where scissor-wielding gremlins cut the wires of biplanes when unsuspecting pilots were about. An article by Hubert Griffith in the servicemen's fortnightly Royal Air Force Journal dated 18 April 1942, also chronicles the appearance of gremlins, although the article states the stories had been in existence for several years, with later recollections of it having been told by Battle of Britain Spitfire pilots as early as 1940.
This concept of gremlins was popularized during World War II among airmen of the UK's RAF units, in particular the men of the high-altitude Photographic Reconnaissance Units (PRU) of RAF Benson, RAF Wick and RAF St Eval. The flight crews blamed gremlins for otherwise inexplicable accidents which sometimes occurred during their flights. Gremlins were also thought at one point to have been enemy sympathies, but investigations revealed that enemy aircraft had similar and equally inexplicable mechanical problems. As such, gremlins were portrayed as being equal opportunity tricksters, taking no sides in the conflict, and acting out their mischief from their own self-interest. In reality, the gremlins were a form of "buck passing" or deflecting blame. This led folklorist John Hazen to note that "the gremlin has been looked on as new phenomenon, a product of the machine age – the age of air". Some experts believe this form of "passing the buck" was important to the morale of pilots. Author and historian Marlin Bressi stated, "Gremlins, while imaginary, played a very important role to the airmen of the Royal Air Force. Gremlin tales helped build morale among pilots, which, in turn, helped them repel the Luftwaffe invasion during the Battle of Britain during the summer of 1940. The war may have had a very different outcome if the R.A.F. pilots had lost their morale and allowed Germany's plans for Operation Sea Lion (the planned invasion of the U.K.) to develop. In a way, it could be argued that gremlins, troublesome as they were, ultimately helped the Allies win the war." Bressi also noted: "Morale among the R.A.F. pilots would have suffered if they pointed the finger of blame at each other. It was far better to make the scapegoat a fantastic and comical creature than another member of your own squadron."
Gremlin Americanus: A Scrap Book Collection of Gremlins by artist and pilot Eric Sloane may predate the Roald Dahl publication. Published in 1942 by B.F. Jay & Co, the central characters are characterized as "pixies of the air" and are friends of both RAF and USAAF pilots. The gremlins are mischievous and give pilots a great deal of trouble, but they have never been known to cause fatal accidents but can be blamed for any untoward incident or "bonehead play", qualities that endear them to all flyers.
See also Ssh! Gremlins by H.W. illustrated by Ronald Neighbour ("Neb" of the Daily Maily), published by H. W. John Crowther Publication, England, in 1942. This booklet featured numerous humorous illustrations describing the gremlins as whimsical but essentially friendly folk. According to "H.W.", contrary to some reports, gremlins are a universal phenomenon and by no means only the friends of flying men.