Gremlins

"There were many things in the Faewild, and while the Elves, Etherites, Dwarves, Gnomes and Goblinoids were cast out, there is still plenty of life in the *hedgerow*. And at times, the Fae come in contact with this world, and they bring with them the *games* they played before the Exodus. Gremlins are regarded as some of the least fae by those that live in the *hedgerow*, but they were always ready to *play* for the Faelords. As such, thousands of Gremlins were always ready to be sent to do their bidding, and many of them were destroyed in the Great War that led to the Exodus, but not all of them. Gremlins are also the easiest Faebeings to fabricate, it seems, and the Faelords use them still in their *games*, especially to torment those living in this reality. The more gremlins you meet, the more they will come to torment you, and in the end you will wish that they take you away to the *hedgerow*, or worst, take those you love to the *hedgerow*. There are ways to get rid of the gremlins, but you must make them forget you if you want to be safe."
Mashduriel, Heron Clan historian, attempting to explain the existence of gremlins to a Terran diplomat.
=== The Gremlins ===
It is hard to understand anything in regards to Gremlins outside the fact that they are extra-dimensional creatures from the same realm as the elves, and that they apparently still serve the ancient lords of those lands. There are apparently many types of gremlins, most kind sharing little in common outside of their small size and nasty demeanor. Most gremlins play pranks on anyone they can get their hands on, some of which are inoffensive but other being extremely dangerous. Gremlins are also known for tempering with technological equipment, making them glitch more than usual or simply causing catastrophic failure in them. While a single gremlin is not much of a threat to an armed individual, the fact that they generally come in large, heteroclyte groups is what makes them dangerous.
Like most creatures still strongly affiliated with the Faeworld, gremlins are extremely allergic to unwrought (or cold) iron, which is somewhat hard to come by in a modern world. Many elves are known to at least own one such weapon, generally a knife, with which they can threaten gremlins that would annoy them. While this has not spread over to most other species, some Terran living close to the Star Empire border have taken a liking to the idea after some gremlin incursions. Another thing that is often used are "gremlin bells", tiny bells which can be attached to various things and in various places in the house, which appears to scare off gremlins.  
While gremlins are sometimes viewed as minor annoyances, the elves often tell horror stories about them, especially in regards to the kidnapping they do for their Faelords. While there are no proof that gremlins actually perform these acts, the omnipresence of this myth in elven, both Imperial and Royal, folklore does seem to give credence to the fact gremlins sometimes are the cause for the disappearance of some children. 
=== The Mite ===
Gremlins are creatures of the Faewild and the *hedgerow* (whatever that really is), and cannot exist in our realm for too long before having to return, probably due to some matter of mystical connection between them and this other realm. Unfortunately for some gremlins, however, it seems that it is not always possible to return to the *hedgerow*. After prolonged exposure to this reality, those gremlins lose most of their supernatural powers and lose a lot of their natural cunning. After a certain time, they finally become fully "acclimated" to this reality and become what is now known as "mites". 
Those degenerate gremlins behave more or less like primitive mammal sentient beings, forming communities in underground locales, like the sewers of an elven planetary hive or a remote cave formation on a Terran colony. They live mostly by stealing what they require to live, along with farming underground crop (like fungus) and raising insects for food. While not hated by the elves per se, they regard the mites as little more than nuisances to be exterminated if possible. There is currently no policy in regards to mite colonies located on Terran planets, but one such occurrence led to an attempt to open a dialogue with the creatures, which resulted in the death of a Terran diplomat. The destruction of the small mite colony was reported 3 days later after a successful operation by the New Macau National Guard.