Vako

Vako were great horned, rhinoceros-like Rahi that roamed the plains of Ta-Wahi and the drifts of Ko-Wahi. They were known for being capable of reaching great speeds while charging, making them formidable threats to any being foolish enough to anger one.

History
Like all other Rahi, the Vako were created by the Brotherhood of Makuta using a combination of Viruses and Energized Protodermis. It is unknown whether other continents of the Matoran Universe had Vako inhabiting them, but Metru Nui was known to be home to a good number of Vako. After the Great Spirit collapsed, Metru Nui was devastated. Due to the Vahki having sealed all of the Matoran population in spheres, the invading hordes of the Visorak were able to occupy the abandoned city without opposition. The Vako, however, were for the most part able to evade capture, and migrated to the island paradise of Mata Nui. During the following millennium spent on the island, some brave Po-Matoran attempted to tame the imposing rhinoceros-like Rahi, but all such attempts ended in utter failure. After the Bohrok swarms were unleashed to "clean" the island, the Vako herds escaped Ta- and Ko-Wahi to return to the now-rebuilt and repopulated Metru Nui.

In the aftermath of the Battle of Bara Magna, the entire Matoran Universe inside Makuta's stolen body was rendered uninhabitable; the Vako herds inhabiting the Matoran Universe were among the many Rahi that escaped the robot onto the surface of the newly-reformed Spherus Magna.

Abilities and Traits
Different breeds of Vako were seen in both Ta-Wahi and Ko-Wahi, each adapted to their respective climates. However, all were known to be extremely dangerous to Matoran and Rahi alike due to their tendency to charge at high speeds; they were so formidable that even Makuta's infected Rahi tended to avoid roaming Vako.