A six-metre tyrannosaur — slim, long-legged, with narrow blade-like teeth instead of bone-crushers, and almost certainly faster than any adult. 'Jane', a famous Montana skeleton, died at about eleven years old. Whether animals like her are teenage T. rex or a separate, lighter species called Nanotyrannus is one of the liveliest arguments in palaeontology, reopened by a 2025 study of a remarkably complete skeleton. Either way, it hunts small, quick prey. Win the duel to escape.