A full-grown T. rex could grow to 40 feet long and 12,000 pounds, but scientists believe that, at birth, these dinosaurs were the size of a mere household cat. Very little information is known about the T. rex's youth. Now, Explorer takes viewers on an epic journey into this bold high-tech animatronic initiative, digging deep into the fossil record for the tiniest of clues to re-create the worlds most accurate, fully skinned, mechanical replica of a walking juvenile T. rex.