Zach Galligan is the young man whose inventor father (Hoyt Axton) gives him an odd Christmas present: a tiny, furry creature that comes with a set of rules: don't get him wet, don't feed him after midnight, and keep him away from direct sunlight. But Galligan breaks the first rule and the damp little critter pops out a dozen little offspring. Then the offspring break the second rule and, overnight, turn from cute furry guys to malevolent scaly guys with world domination on their mind. The only way to stop them: rule three. But it's an anxious (and extremely funny) battle to make it to daylight--and the bad gremlins find ways to multiply over and over.