Menō

Though Zansuru labels him a 'Tirano' in a nod to the tyrannosaur, the manga and anime draw Menō far closer to a velociraptor, complete with a blue stripe tracing each flank. He walks upright on two legs and stands only about eighty centimetres tall, yet his body stretches beyond two metres from snout to tail-tip. Tough, hide-like skin studded with horns covers him, and he is armed with sharp claws and cone-shaped fangs.

As a born hunter, Menō is deadly in close quarters, driving strong jaws and razor claws into his prey. His legs coil like springs and launch him dozens of metres in a single bound, while a swing of his tail can splinter timber, giving him a third line of attack when his teeth and claws are turned away. Being small for a dinosaur, he favours ambushes on larger beasts, striking at the neck and legs to fell them fast; against ordinary humans he simply overwhelms them. His claws carry a poison that creeps through the victim's chakra pathway system, first bringing dizziness and sluggish movement and eventually a total, if temporary, paralysis. He often scratches an enemy and then withdraws to let the toxin do its work. Most dangerous of all, the reincarnation that revives him renders him immortal, so wounds that would kill an ordinary animal simply mend by the next morning.

The paleontologist Zansuru, having cracked a method for raising the dead, plans to field an immortal army of dinosaurs for Redaku's Prime Minister and enlists Jiji to help him. Menō is the trial revival, kept on afterward to patrol the Astronomy Research Institute and execute anyone who attempts an escape. He performs the duty so ruthlessly that the guards grow careless, trusting fear alone to hold the inmates. One prisoner is Sasuke Uchiha, who studies the creature by night. Their first clash goes nowhere: genjutsu will not take hold, and Sasuke resorts to an ice blade, cutting Menō and stabbing his torso, only for the wounds to vanish by dawn. A later encounter leaves Sasuke poisoned by a claw, and Sakura has to purge the toxin from him.

Piece by piece, Sasuke grasps that Menō is a reincarnated soul trapped in a body it cannot fully govern. When Zansuru sends the beast to kill him, Sasuke refuses to fight, instead calming Menō, cooling his lantern burns with ice, and apologising for their first duel. He promises to return Menō to the peaceful death he was torn from if the dinosaur will aid him, and this time his genjutsu, reinforced with transferred chakra, takes hold. Won over, Menō turns on the rampaging herd, shielding prisoners such as Ganno and even overpowering an adult of his own kind, since Sasuke's chakra makes him stronger. Zansuru seizes control of every dinosaur at once, but Sasuke hurls Menō onto the giant Titan and lures it into a lake, where a strike to its tendons drops it into the water; Zansuru drowns trying to save it. With the scheme broken and Jiji beaten by Sakura and made to surrender, the revived creatures are sent back to the afterlife. Menō's body crumbles to dust, and his departing spirit nuzzles Sasuke in farewell before it fades.