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