Creepy Crawlers (or Thingmaker) is an activity toy made by Mattel, beginning in 1964. The toy consists of a series of die-cast metal molds resembling various bug-like creatures, into which is poured a liquid chemical substance called "Plastigoop", which comes in assorted colors. The mold is then heated to about 390 °F (199 °C) on an open-face electric hot plate oven. The Plastigoop is cured by the heat, and when cooled forms semi-solid, rubbery replicas which can be removed from the mold.