Gremlin (グレムリン?) is a recurring demon in the series.
In the 1920s-1950s, Gremlins were created as a legend in the British Royal Air Force to explain mechanical problems. Gremlins are tiny, goblin-like creatures that are mischievous and like to play with machines, often breaking them in the process. These beings became more well-known thanks to the 1984 horror/comedy film Gremlins and its 1990 sequel, which depict them as the main antagonists.
"Origin: England. A malevolent creature that breaks machines. They used to be good creatures that helped with inventions. But when their help went unacknowledged, they turned to playing pranks on humans. They are relatively new demons, as mythologies go."
—Shin Megami Tensei A-Mode DDS Dictionary
Shin Megami Tensei: Strange Journey
"A mischievious sprite that likes to wreak havoc on machines and tools. It is said that during World War II, Gremlins were found when examining plane failures. They are troublesome creatures but are known to be useful at times. Gremlins were said to have helped Franklin's proof of lightning as electricity."
—Shin Megami Tensei: Strange Journey compendium
Shin Megami Tensei IV
Gremlins can be found in the lower levels of Naraku. They can teach Flynn the Mabufu, Dream Fist and Sukukaja skills through their Demon Whisper. A Gremlin will evolve into Raiju at level 14. Gremlin is one of the demons needed in order to summon Plasma through special fusion.
Shin Megami Tensei IV Apocalypse
Gremlins appear in the initial aboveground areas of Ueno. When leveled up, they can teach the Bufu, Dream Fist and Zio skills.
Devil Summoner: Soul Hackers
"A mischievous sprite that likes to wreak havoc on machines and tools. It's said that during World War II, Gremlins were found when examining plane failures. They are troublesome creatures but are known to be useful at times. Gremlins were said to have helped Franklin with his famous kite experiment."
—Devil Summoner: Soul Hackers 3DS compendium
Megami Ibunroku Persona
Gremlins are demons of the Jaki Order and start appearing early in the game. A Gremlin has replaced the Lieutenant that Masao was acquainted with and attempted to kill the party when they helped free Masao and Hidehiko. Gremlins start showing up in random encounters upon reaching the Abandoned Factory.