GR -Giant Robo- Pilot

Giant Robo | GR -Giant Robo- Pilot | GR -ジャイアントロボ- パイロット

The pilot for GR: Giant Robo. However, there were significant changes between the pilot and the actual show, including a different writer and a different director. Thus, the special is less a promo for the series than an alternate version of how the series might have looked. (Source: Orphan)