Gremlins, as depicted in the 1984 movie of the same name, are not real. The creatures in the movie were animatronic puppets that were controlled by puppeteers. Special effects were dubbed in to make them seem lifelike.
The creatures that multiplied when they got wet, went crazy if fed after midnight, and melted in bright light may be fictional, but scientists recently re-discovered a small primate in Indonesia that earned the nickname "Gremlin" because of its uncanny resemblance to the movie creatures. The tiny animal was thought to be extinct for nearly 100 years and has the same big bulging eyes that marked the Gremlins' appearance.