Jaller is a lovable not-smart (Later smart) red Toa hero of the Toa Mahri with a speech impediment. He's the leader of the Toa Mahri and represents the Leo constellation out of the group. He was once a Matoran who was friends with another Matoran named Takua. He and the other Toa were searching for the Kanohi Ignika. In 1999, he failed an audition for The Brak Show because he was too stupid, but in 2007, he realized that YouTube had been invented, so he started his own YouTube show. He and the rest of his team were teleported back to Metru Nui due to Matoro's sacrifice.
He and Hahli have been in love with each other for a while. They also decided to do weird stuff after the sacrifice. Did we mention his color is red?