In 1984, director Joe Dante's Gremlins was such a scary PG movie that the PG-13 rating was created soon after. It was a Christmas horror comedy about Billy Peltzer (Zach Galligan) and his new pet, Gizmo (voiced by Howie Mandel), a mystical creature called a mogwai. When Billy failed to follow the mogwai rules, Gizmo accidentally spawned deadly gremlins that went on a rampage. The sequel, Gremlins 2: The New Batch, is set to leave HBO Max in a few days. It's also our pick for the great movie you need to watch before it leaves in December.