gremlin

an imaginary being usually having a small human form and magical powers during the World Wars, fighter pilots adopted the fanciful notion that gremlins were responsible for mechanical failures on their planes Synonyms brownie, dwarf, elf, faerie (also faery), fay, gnome, goblin, fairy, hobgoblin, kobold, leprechaun, pixie (also pixy), puck, sprite, trollRelated Words little people; kelpie, nixie; changeling; imp; banshee, ghoul, hag, ogre