This sequel to the classic Tremors that starred Fred Ward and Kevin Bacon, has Ward's character Earl back monster hunting in Mexico with new partner Grady has a cryptid moment with Helen Shaver's character Kate realizing how old these creatures really are on planet earth.  Despite Earl's proclamation that they he thought they were from outer space, it turns out that not only are they one of the oldest lifeforms on the planet...they have a very interesting mode of reproduction, which no one in the story anticipates....because no one has ever really seen them before!  The essence of Cryptozoology!