Kamen Rider 0 (Unused Rider)

Kamen Rider 0 (仮面ライダー０号) was an unused Kamen Rider from Kamen Rider created by producer Tohru Hirayama. He is a prototype of Kamen Rider 1 made by Professor Midorikawa, however, his surgery was unsuccessful and killed him immediately.

Legacy
The name of Kamen Rider 0 will later used on Skyrider and Black's early conception.