Yamoshi

Yamoshi (ヤモシ Yamoshi) is an ancient Saiyan who could transform into a Super Saiyan long before Goku could. After his death, his spirit wandered in search of six pure-hearted Saiyans, to create the ceremony that would birth the first Super Saiyan God.
He was immortalized as the Legendary Super Saiyan (伝説の超サイヤ人 Densetsu no Sūpā Saiya-jin), thought to be nothing more than a myth until Goku's first ascension during his fight with Frieza one thousand years later.