Make a stone or metal octagon out of Dino gateways, but leave one for the behemoth. Put a gate in the behemoth, but not the regular ones. Set the behemoths pin code to your preference and close the gate with the keypad AFTER luring the Rex inside. The Rex canโ€™t fit through the regular Dino gateways, but you can, allowing a safe easy tame.

More Rex Taming & KO Tips