|Home world:||Planet Earth|
|First appearance:||Ultraman Dyna Episode 16: "Battle! Monster Island"|
|Latest appearance:||Ultraman Retsuden Episode 49: "Dyna, Battle! Monster Island"|
Subtitle: Hyper Clone Monster (ハイパークローン怪獣 Haipā Kurōn kaijū?)
- Height: 73 m
- Weight: 75,000 t
- Origin: Zarina Zone
Neosaurus was originally an underground monster who was found sleeping by Professor Otomo, a former TPC scientist who had banned due to his studies for creating his own monster. The scientist then took him to his lab and injected several cells of different monsters and a controlling device into him. The scientist then created clones of two other monsters: Silvergon and Sildron, as test subjects. Due to the scientist's discovery that Hanejiro had the intelligence of a second grader, the scientist kidnapped Hanejiro and took him to the secret island where he kept his hyper clone. As soon as Super GUTS found out about his crimes, Asuka, Kouda, and Nakajima were dispatched to find the island. Due to the Island's magnetic field, the crash landed there and encountered a battle between Clone Sildron and Clone Silvergon. After Silvergon killed Sildron, he attacked Super GUTS. Then, the Scientist's assistant was caught by Asuka, who brought them to the main lab. As the Scientist revealed what he has been doing, Kouda and Nakajima began to try and arrest him, but a quick electric web shielded the Scientist. Asuka overheard the conversation when Kouda left his radio on and rushed to their rescue Silvergon then appeared and Began to attack the lab as well, attracted by Asuka's appearance. As the last resort, Professor Otomo released Neosaurus, who killed Silvergon by throwing him onto the lab, then killing him with his Helix beam. Unfortunately, Neosarus never got Hanejiro's intelligence, and since the lab was destroyed, Neosaurus malfunctioned, and killed the scientist by stepping on him. Just before he could kill Asuka, Dyna appeared. Unfortunately, Neosaurus's spikes prevented Dyna from attacking, and he himself began to beat Dyna with his tail. After Dyna fell, Neosaurus then stepped on the giant. It was then when Dyna transformed into Strong Type. A short mash-up later, Neosaurus fired his Helix Beam, and Dyna dodged behing his tail. Raising his tail up, Dyna succeeded in blowing off the Kaiju's tail, and a beam showdown ensued. Dyna's Granate Bomber won, and Neosaurus fell over, and exploded.
Neosaurus later appeared as a flashback in episode 47.
- Suit actor: Toshio Miyake
- Neosaurus's costume was created from a heavily modifyed Dexador costume.
- Neosaurus's roar is a modifyed Rodan roar.
- His name in Greek means "New Lizard".
- Neosaurus is in tribute to Jirass.
- In the 1966 Batman TV series, in one episode the villain (Egghead) attemps to hatch a dinosaur egg that belonged to a creature called Neosaurus.
- This Episode was later featured in episode 49 of Ultraman Retsuden: Fierce Battle! Dyna in the Monster Island!!.
- Helix Beam: From the two objects on his chest, Neosaurus can fire a blue spiral-shaped beam of energy. It's very powerful and it has a homing effect. This attack is also known as "Homing Beam".
- Spikes: The spikes on Neosaurus's shoulders are sharp enough to harm Ultras.
- Tail: Neosaurus's tail can constrict opponents.