Some of the performances were shot on the Courthouse Square and Colonial Street sets of the Universal Studios Lot in Universal City, California (Mrs. Deagle's house was one such set as well as the opening street scenes in Chinatown, which were filmed on the Warner Bros. Studios backlot). This required fake snow; Dante also felt it was an atmosphere that would make the special effects more convincing. As the special effects relied mainly on puppetry (an earlier attempt to use monkeys was abandoned because the test monkey panicked when made to wear a gremlin head), the actors worked alongside some of the puppets. Nevertheless, after the actors finished their work for good, a great deal of effort was spent finishing the effects. Numerous small rubber puppets, some of which were mechanical, were used to portray Gizmo and the gremlins. They were designed by Chris Walas. There was more than one Gizmo puppet, and occasionally Galligan, when carrying one, would set him down off camera, and when Gizmo appeared again sitting on a surface it was actually a different puppet wired to the surface. These puppets had many limitations. The Gizmo puppets were particularly frustrating because they were smaller and thus broke down more. While Walas recommended making the "mogwais" larger to make their creation and functioning easier for the special effects team, Dante insisted on keeping their size small to enhance the cuteness of the creatures. Consequently, to satisfy the crew, a scene was included in which the gremlins hang Gizmo on a wall and throw darts at him. This was included on a list that the crew created known to them as the "Horrible Things to do to Gizmo" list.