As a Matoran,Tridox was a carver in Nui Metru Nui who carved statues for public areas,such as the Coliseum.He was fascinated by the teams of Po-Matoran that had smoothened the walls of the Catacombs.He wanted to be one of them very badly,and one day left for the Catacombs.He got lost on the way and ended up swimming down the River Causs as it swept him away.He ended up in Nortre Nui,and lived there for several years.