I noticed a lack of gremlins on Fim and it even applies to fanart. very few artists have designed an idea of gremlins would look like.
 
So let Eightball tell you a little about his species:
 
 
A Gremlin is a mischievous little creature that fools around with technology and ultimately renders it useless. Despite their Love of this and other pranks, gremlins are never malicious. If a pegasus actually starts to crash from their presence, they will do what they can to help the flying pony land safely. Unlike the more common dragons which are reptilian and changelings which are insectoid,gremlins are fully mammalian. A gremlin has the head of a pony, the front teeth of a rodent and the body of a monkey with shaggy hair on their heads. Also unlike changelings, the good natured gremlins have independent thought and each one is different. Most gremlins have pony eyes as well. Unlike many of the folkloric creatures in Equestria, gremlins look more comical than ugly; betraying the fact that they are mostly harmless. Originally thought to be a myth, gremlins were proven to exist only 80 years ago; when a zoologist from Canterlot stumbled upon one of their villages. Although gremlins tamper with machinery and the flight of pegasus ponies, they truly do not mean any real harm and will do anything it takes to make amends. On a related note, though they are among the rarest species in Equestria many repair shops are run by gremlins who will work their trade in exchange for their favorite foods. As seen in the picture above, gremlins tend to wear futuristic jumpsuits and bowties. All in all the gremlin is one of the most singular beings in the land. (Magical Lifeforms of Equestria, vol. 1, A - G)
 
Eightball is an outcast among his own kind. In fact, he was kicked out of his village because of his constant bumbling and the fact that he built a strange remote that has an unknown purpose. Eightball’s ultimate goal is to go home. He has roamed Equestria for years after being exiled and is homesick. He will not rest until he can convince his fellow gremlin’s that he is worthy of being among them.