Professor Nikaido (二階堂教授 Nikaidō Kyōju), alias Dr. Nakamura (中村博士 Nakamura Hakase), was a dinosaur obsessed mad doctor. He appeared in episode 10 of the original Ultraman TV show, titled "The Mysterious Dinosaur Base".
After rumors of his death at the jaws of the Loch Ness Monster, a 'close friend' of Nikaido, named Nakamura, took up his research. Obsessed with the idea of giant saurian beast roaming the Earth once more, Nakamura created and raised for fifteen years, the monster Jirahs and kept the beast in Lake Kitayama. However, the food that the frilled dinosaur ate caused the local fish population to explode in size, attracting attention of the Science Patrol.
After Nakamura was interviewed by a reporter, he found out that his baby, Jirahs, was now surfacing unintentionally when two fishers threw chemicals into the lake. Nakamura then took the female reporter and Ide hostage as he went to try and calm his rampaging dinosaur.
When the Science Patrol began to attack Jirahs, the mad doctor stepped in and tried to stop them, and after Cap asked him 'What would Professor Nikaido think of his mad abomination', Nakamura cackled and ripped his own face off, revealing Professor Nikaido! The professor, mad with his obsession with dinosaurs, ran towards Jirahs, only to be trampled.
After the fight between Ultraman and Jirahs concluded, the dying Nikaido crawled towards Jirahs, screaming the name of his creation before he himself died.
- Professor Nikaido is the first human villain in the Ultraman Series.
- While at the start of his debut episode, it is rumored that Nikaido was killed by the Loch Ness Monster, the original Japanese version of the episode states that in reality, he's still in Japan. Contrary, however, the English dub of the episode stresses that both Jirass and Nikaido are present in Scotland, where the Loch Ness Monster legend originated from.