Great Ape (大猿, Ōzaru; lit. “Great Monkey”), or Oozaru, is a giant, monkey-like creature that Saiyans can transform into to increase their enormous strength. Originally in the series, the Great Ape was a transformation for Goku, being a parody of a monkey king character named Sun Wukong from the novel The Journey to the West; however, the Great Ape is discovered to be a transformation that is only accessible to characters who possess heritage from the Saiyans later in the series.
ETA – 4th Quarter of 2019*
*NOTE – ETA are subject to change without notice.