The 10th flying saucer monster summoned from Black Star by the Black Directive. Nova emits a red noxious gas from its mouth that causes people to go violently insane, and attacks with its whip-like tentacles and sickle.

Nova flew to Earth in secret and disguised itself as a teru-teru bozu Japanese doll. Disguised as a doll in a park, Nova secreted the red violent gas, causing people to attack one another. Nova changed to child-size, and hypnotized Toru Umeda to take him around town so it could infect more people with its violent gas, sending the town into chaos.

Gen Otori and Toru’s foster family, the Miyama’s helped to convince Toru to come back to his usual self. Nova retaliated by turning giant and attacking the town, with the defense force’s attacks having no effect on it.

When Ultraman Leo arrived, Nova attacked him with beam attacks and then strangled the Ultra with its tentacles, but Leo countered with his Shooting Beam and Energy Light Ball combo, killing Nova in an explosion.