Nokama encountered the creatures during their trip to Mata Nui, witnessing two of them attack a sea slug Rahi. Later she named them Manas, the Matoran word for "monster".Teridax controlled two Manas that were later freed (these same two were later encountered by Toa Onua and Turaga Whenua). Karzahni had several Manas in his realm. These Rahi were also attracted to heat.
When the Toa Mata journeyed to Teridax's lair in Mangaia, they encountered a group of Manas controlled by Teridax. The only way the Toa could defeat them was by merging into Toa Kaita: Wairuha and Akamai.
At one point, Onua was able to pit a Kofo-Jaga against some Manas to defeat them.
- The Manas are the only BIONICLE sets that could be controlled by remote control.
- The two Manas included in the set could be combined into a Mana Ko.
- The Manas was released in 2001.
- The Manas' set number was 8539 and had 442 pieces. (As a whole, not for each Manas.) This means that there was probably 221 pieces in one Mana.
- The Manas set is the most expensive set recorded along with the Skopio XV-1.
- In the wild, Manas tended to turn on each other when they ran out of opponents to fight.
- In the Mata Nui Online Game, there were several Manas on the way to Mangaia that Toa Kaita had to battle. They destroyed them by destroying strange poles that controlled them.