Mr Alien had a wooden armature with aluminum wire joints (they snapped five times during the course of filming). The muscles were foam and the skin latex. The tongue (wich made a few appearances) was plastiscine coated with petrolium jelly. The cockpit of the UFO was cardboard, with christmas lights and the innards of an old radio for decoration. Outside the windshield was a green screen, to allow for Johan inserting images of space.