Steel Jeeg (鋼鉄ジーグ in kanji, transliterated as Kotetsu Jeeg in romaji) is an anime series created by manga artists Go Nagai and Tatsuya Yasuda, and produced by Toei Animation. It was first broadcast on Japanese TV in 1975. The series lasted for 46 episodes. Steel Jeeg also ran as a manga in several children's publications. The opening theme Kotetsu Jeeg no Uta is sung by Ichiro Mizuki

http://en.wikipedia.org/wiki/Kotetsu_Jeeg