A gremlin is a folkloric mischievous creature that causes malfunctions in aircraft or other machinery. Depictions of these creatures vary. Often they are described or depicted as animals with spiky backs, large strange eyes, and small clawed frames that feature sharp teeth.
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.[1][2] Later sources have sometimes claimed that the concept goes back to World War I, but there is no print evidence of this