Howie Mandel provided the voice for Gizmo, and prolific voice actor Frank Welker provided the voice for Stripe. It was Welker who suggested Mandel perform in "Gremlins". The puppets' lines were mostly invented by the voice actors, based on cues from the physical actions of the puppets, which were filmed before the voice work. When developing the voice for Gizmo, Mandel explained, "was cute and naive, so, you know, I got in touch with that... I couldn't envision going any other way or do something different with it". The majority of the other gremlins' voices were performed by Michael Winslow and Peter Cullen, while the remaining voices were done by Bob Bergen, Fred Newman, Mark Dodson, Bob Holt, and Michael Sheehan.