When I was growing up, I remember having one of those creepy crawlers bug-making factories.
You poured a resin called Plastigoop into molds, put it in a hot plate to cook, then let it cool and set.
It was really fun trying to make the creatures look realistic with different colors of the Plastigoop.
They changed the formula around so that instead of heating the resin with the hot plate oven, you’d heat the resin, then pour it into the molds to cool and set.
These days, if I want creepy crawlers, I just leave the dishes out for weeks.