For Jumanji Dave Penacas had to create the mechanisms for 13 mechanical grant spiders that had to be able to walk across the floor under their own power. This meant miniaturizing battery components as well as a custom mechanical cam system which drove the legs independently. The spiders could be driven around the floor like remote control cars. If fact, for one of the bi gest scenes where we had multiple spiders running on the floor we had several puppeteers standing off set with radio control boxes watching monitors trying to make sure that their spiders weren't crashing in an arachnid demolition derby.