The gremlin is mischievous and mechanically oriented, with a specific interest in aircraft. Many airmen claim that the gremlins were responsible for sabotaging their dirigibles and hot-air balloons.

Gremlins are members of the Supernatural and Fantastic Wayfarers Association.

The Great Monster Uprising of the Second Age of Magic saw the most infamous of all gremlin invasions. On one Birthday, a horde of gremlins originating from Gurth infiltrated the domains of the Implementors, where they began to tinker with the great machines that the Implementors used to run our world. Parameters were tweaked and the behavior of monsters were altered. The Implementors were the first to notice these anomalies when abominable snowmen were seen wandering the hottest deserts, mucusoids were drying out, and grues were spotted sunbathing. While these were fixed quickly, the massive amount of changes needed to be reverted was massive. The Implementors were overburdened with trying to fix all of the damage caused by these sneaky villains. (Some historians have speculated the the Implementors purposefully knew about the gremlins and allowed them to roam their domain in order to be entertained by the random calamities which befall the mortals on the surface below.)

Almost every day for two weeks, the gremlins would change things subtlely enough that many of them went unnoticed by the Implementors. Thus these demi-gods hired any adventurer that would heed their call to find them. Knowing that they would be required to explore every corner of Zork to uncover these disturbances, the Implementors handed out tremendous magical rewards that granted temporary endurance so that they could go out and find more. All located gremlins were flattened with an insanely oversized mallet.

On that first Birthday, one gremlin was responsible for the disabling of traps, mazes, and puzzles from many regions all across Zork, with an exception of most dungeons and underground locations. As the lack of these snares was favorable to all adventurers of the time, there was much cursing and lamenting throughout all the world when this gremlin was smitten by the Implementors. The other had the profound effect of causing snow wights, Christmas tree monsters, and abominable snowmen to tread the White Cliffs Beach without melting (and additionally to prey upon the other monsters present in the region).

The next day (Frob Day), the influence of the gremlins had caused rebel nymphs to overrun the Dark Forest and a band of dryads to steal Terazarg. By Star Day, the Implementors, following the leads of adventurers, found where the dryads had hid their big shiny weapon and confiscated it. The survivors armed themselves with painted sticks and tree trunks. But in the meantime, new gremlins were unleashed on the world which inspired dragons to leave their territory and migrate into the Granola Mines, while Yoruk's First of Fury began to spout fire.

It took the next two days and heavy work to route the dragon infestation out of the mines. But new gremlins were on the loose that Mud Day. The Port Foozle Drunk was infused with a temporal ability to teach two alternate skills, “Houdouken” instead of “Dutch Courage” and “Falcon Punch” instead of “Headbutt.” The age restriction was dropped in the Port Foozle Casino, allowing minors to enter.

By Grues Day morning, the Drunk had been told off for teaching people these forbidden skills, and the underage visitors of the casino were forced out. But in the city of Borphee, a powerful gremlin ousted the Witch from her home for the remainder of the day, where it instead taught new magical tricks in her place. Elsewhere, invasive species were seen at the Flathead Fjord: dragons, quelbees, corbies, giant toads and giant crocodiles were predators to several of the following species, rendering them extinct until they could be replaced by the Implementors the following day: apemen, cyclops, dornbeasts, hellhounds, horrors, mucusoids, giant slugs, ogres, nymphs. (Possibly unrelated to the gremlins, lucksuckers were thought to have permanently moved into the Port Foozle Casino on this same day, but they were only seen there temporarily.)

A new pair of gremlins ran around causing havoc on Wands Day. The functions of certain offensive spells were changed (the names of least five were once recorded down). A gremlin who took pleasure in lurking underground was responsible for alerting the authorities to the whereabouts of the infamous pirate, Long Jim Zorkmid, who was then quickly detained and imprisoned in the Antharian Caves for his crimes against Anatharian shipping. He cleverly escaped the following day.

Late of the night the second Birthday of the infestation, the gremlins of the previous day were safely removed, but two fresh villians were running around waiting to be discovered. Rocs were morphed into big birds while the FrobozzCo Premium Nametag was altered into the FrobozzCo Premium Gremlin.

The second Frob Day, the occupations of various adventurers were altered, while cyclops were suddenly inspired with a rare notion of politeness -- the signs they carried about read "Pardon?" instead of "I can't hear you!" These gremlins were not located until Sand Day.

Reports of gremlins abounded on Sand Day. Snow wights, Christmas tree monsters, and abominable snowmen were once again enhanced with the ability to tread warm climates without melting. They settled in the Peltoid Valley for the day. It was discovered elsewhere that Gurth was a source of gremlins for all the land. While this source was clogged and the gremlin infestation ended, the final two gremlins were not detected until Mud Day. These two creeping pests distributed candy canes to nymphs and defamed the Magnificent Bozbarland Zorkmid Lottery. When the two were detected and caught, the invasion had ended. The machines were completely restored
and all aberrancies were mended.

SOURCE(S): The Zork Chronicles, Legends of Zork