Nui-Jaga were huge scorpion Rahi with powerful stingers, whose strikes could be fatal. Most were slow and not very bright. They could be tricked by showing their reflection on a rock or wall. This was an advantage to Po-Matoran that hunted Nui-Jaga stingers. Being aggressive Rahi, they would attack the reflection, thus trapping their stingers. Nui-Jaga stingers were considered valuable in Metru Nui, but most of those who went after them never returned. Their known colors are blue and purple. They usually lived in desert but have also been found in volcanic areas.
Once Takua was followed by a Nui Jaga and used a Muaka to get the two into a fight so he could escape. Jaller, Onepu, Hewkii, Macku, Kongu, and Matoro once formed a Matoran Nui to fight off a Nui-Jaga.
- The Nui-Jaga was set number 8548.
- The set contains 226 pieces.
- Excluding the 2001 McDonald's promo Onepu, the Nui-Jaga is the first and only BIONICLE set that the main color is purple.
- If a trigger was pulled on the underside of the Nui-Jaga, it's head would retract and the tail would snap forward in a stinging motion.
- Two Nui-Jaga could be combined to create a Kahu.