Terohk was once a Steltian who was transformed into a Vrai by the Vrai mutation virus. Fearing the worst, he fled Stelt before it was destroyed by Blackout. He was on the run for many years, an outcast because of his appearance, until he realized that the only place safe for him would be a place away from civilization. He stole a small boat and sailed the seas by himself until he landed on one of the unexplored, empty islands south of the Southern Continent where he lived for the remainder of his life.
One day a starving Ga-Matoran named Natero arrived on the island in a small boat. Instead of attacking her like his Vrai side suggested, Terohk's Steltian side recognized her as something he should care for, as she was defenceless and posed no threat. Terohk nursed the Matoran back to health, teaching her how to hunt small creatures on the island to eat and survive. They formed a close bond, and would frequently throw things in a pool of energized protodermis for fun.
Terohk was killed when the pool transformed into the homicidal Energized Protodermis Entity. Upon becoming a Toa, Natero would combine Terohk's name with hers as a way of remembering him.
- Only having appeared in backstory, Terohk hasn't appeared in the RPG, but the potential for him to appear in flashbacks/alternate universes remains.