Zu Gooma Gu is treated very badly by the other Gurongi. He's not allowed to take part in the game so he cannot advance. The rose lady and the Me treat him with contempt. (Until episode 36) Zu Gooma Gu cannot stand sunlight, so during the day, when in human form, he wears dark clothes and carries an umbrella to shield himself from the light.
Since he's not sent out to kill humans he schemes to increase his own power without playing the game. He succeeds (episodes 36). Becoming a rebel he attacks the rose tatoo lady (episode 37). However, even with his new power he's no match for N Daguba Zeba, the Gurongi leader defeats him easily (episode 39).
Zu Gooma Gu out lives all the other Zu and all the Me. He's still around after 6 of the 10 Go have been killed. Only N Daguba Zeba and the rose tatoo lady live longer than Zu Gooma Gu.