Beast archaeologists unearthed the three talismans of the three sacred sigils, lost long ago in the War on Planet Beast. After restoring these to the Beast Temple they unwittingly opened a portal in time. Through this gateway Beast Geneticists were able to harvest living DNA from the Megafaunic Beasts of the Pleistocene era, and transport it back to Planet Beast. Here the DNA was hybrid with Battle Beast tissue in saline tanks, to create the Ice Age Squad, huge hulking beasts who walked upright, but retained their primordial survival instincts and the sheer strength and stamina of their ancestors.
Stone Cold Steve Cobra smells what the Rock is cookin'.