Robo Rider's Birth (ロボライダー誕生 Robo Raidā Tanjō) is the fifteenth episode of Kamen Rider Black RX. It's the second part of a four episode story arc. It features the debut appearance of RX's first alternate form, Robo Rider, which would be followed by Bio Rider two episodes later. It also features the first appearance of Joe the Haze.