Neko Majin Z, or just Z, debuted in Akira Toriyama's self-parody manga of the same name.
Neko Majin Z in Video Games
Z's first video game appearance is in the Japanese version of Dragon Ball Z: Budokai 2. In an extra level of Dragon World that is exclusive to that release, he is one of the map icons, and will transport a player to another destination upon reaching him.
Z's role expanded with the Japanese version of Dragon Ball Z: Supersonic Warriors 2, where he was an unlockable support character for battle.
Z finally became playable in Dragon Ball Heroes with a card that released on June 4, 2014.