The original line of toys, resembling dinosaurs, was released in Japan, Europe and the United States in the 1980s. Initially, the Zoids had a 'Battle Story' that was told in text on the back of the model boxes, and in 'fanbooks' and catalogs. The Zoids franchise also includes five anime series (starting in 1999), three manga series, and multiple series of electronic game, most of which inhabit their own unique continuities independent of the others. Two of the more recent toy lines have been tie-ins to the anime series.
Released in Japan in 1982, the Mechabonica toy line was technically not a Zoids line, but is counted so by collectors as it consisted of three models that would later be re-released as the first three Zoids, (Garius, Elephantus and Glidoler). The line was not very successful, and was quickly dropped by TOMY, which released the line in the United States and Europe the next year, under the name Zoids. The line was far more successful than Mechabonica, which led TOMY to reintroduce the line in Japan under the new name.
Later, a pair of original Zoids were created exclusively for the European and North American markets, the Power Zoids Tank and Serpent which were never released in Japan. Other Zoids like the Bigasaur (renamed to Giant ZRK) were also released. Radio Shack released the Mammoth Zoid in the US at the same time. While not a part of the release, it is generally counted with them. The Original American Release is commonly abbreviated as OAR by fans and collectors.