Gizmo was first seen in the original Gremlins film when Randal Peltzer 'purchased' it from Mr. Unlike the rest of his species, Gizmo is kind, friendly, and harmless. He is a brown and white mogwai who likes to sing and watch television. Gizmo was the source of all the gremlins to appear in the films. The Gremlins shown in the films are killed via a gas explosion in a cinema the first film, and via electrocution in second film. Gremlins can be killed particularly easily. Gremlins also display little care for their own species or others, willing to shoot their own kind to get a laugh out of it. Gremlins are very anarchic creatures, although some can seemingly be doing it for fun, whilst others like Stripe are more deliberately sadistic and violent. Gremlins may keep some of their physical features from when they were Mogwai. Gremlins are tall, scaly-skinned creatures with large ears resembling bat wings, have fanged mouths, and a seemingly instinctive desire to cause havoc at the cost of humanity. Upon feeding after midnight, the Mogwai become encased in cocoons and go through a metamorphosis into the Gremlin form. Mogwai seem to instinctively desire to eat after midnight in order to advance to the Gremlin stage of their evolution, the original batch in the first film tricking Billy Peltzer into feeding them after midnight by altering the time on his alarm clock. A Mogwai spawns more Mogwai, a Gremlin spawns more Gremlins). However, the creatures will spawn the same creature (e.g. The reaction with water, causes Mogwai or Gremlins to spawn other Mogwai. The Gremlins are shown to be afraid of simply lit matches and fire. Gizmo shows a deep dislike towards bright lights. If exposed briefly, a Mogwai or Gremlin shows fright.
The reaction causes a Mogwai or Gremlin to either be killed via a gruesome melting process, as seen with Stripe in the first film, until the creature's own skeleton melts away.