Tren Krom was the powerful entity who controlled the universe in the Great Spirit Mata Nui's absence. Prior to the coming of Mata Nui, Tren Krom dwelled in Karda Nui along with the Av-Matoran.2
Notes
Many inhabitants of the Matoran universe believed that Tren Krom did not really exist and was no more than a legend from antiquity. However, some, such as the Brotherhood of Makuta, knew well that Tren Krom was real. Tren Krom was greatly feared. Meeting him was known to drive beings insane.3
According to Mutran, Tren Krom's appearance was that of a scarlet mass, with a "face that was not a face," tentacles lined with tiny, sharpened hooks, and eyes that were little more than holes in a gelatinous skull. Tren Krom's voice made Makuta Teridax's voice sound pleasant in comparison. He was utterly alien to any form of life in the Matoran universe. His mind was far beyond Mutran's own.3
Tren Krom's island had a deserted, rocky beach. Tren Krom himself could be found inside a cavern on the island.3
Noises could be heard from outside Tren Krom's cave that sounded like breathing through mud and slithering. Tren Krom's voice was unlike anything Brutaka's team had heard before. It sounded like the slimy, repulsive sound made when a nest of feeder worms was disturbed. Even Brutaka had to suppress a shudder. At a glance, what Brutaka saw of Tren Krom was a writhing, crimson mass of tentacles emerging from a gelatinous central core, with two dead yellow eyes that somehow followed every movement without ever moving themselves. Brutaka sensed that to gaze for long at Tren Krom would be to invite madness. Tren Krom seemed to have merged with the stone floor and walls of his cave over time, becoming one with his place of concealment. A stench of decay hung over everything. Tren Krom could mentally probe other beings, though Brutaka's mental training allowed him to resist. The sound of Tren Krom laughing made one wish for death.4
Tren Krom was of the substance of the Matoran universe, and he walked there long before even Mata Nui himself. After his exile, there was a Tren Krom known in legend, though important details about him were left out. Before Mata Nui was born, the Great Beings created one being who was purely organic: Tren Krom. The Great Beings taught Tren Krom the ways of the universe they were creating and placed him in its core. Tren Krom was to remain there, maintaining heat, light, and all the forces that made the universe whole. However, his time was always to be short, as his role was to shepherd the universe until Mata Nui was prepared to take power.4
When the time came, Tren Krom was exiled to an island and bound to the rock. Over the next 100,000 years, his visitors were few in number, and Tren Krom was eager to learn about the outside world from them by probing their minds. Tren Krom could pick someone up in one of his tentacles and sift through a lifetime's worth of memories in an instant. This was an agonizing experience that made Lariska scream. The victim glimpsed Tren Krom's mind as well.4
Tren Krom could also project sickening images into the minds of all those nearby.4
When Carapar tried to sneak up on Tren Krom and attack him with a sword, a third eye suddenly appeared on Tren Krom looking right at Carapar. A beam of energy shot out of the eye, and Carapar shattered into fragments as if made of crystal.4
Tren Krom could withdraw his tentacles by wrapping them around the core of his body.4
Tren Krom was the ancient entity who oversaw the universe prior to the coming of Mata Nui.5
Gorast's region, which included the fearsome Tren Krom Peninsula, was inhabited by monstrous creations of Tren Krom himself. Gorast alone had done battle with these beings.6
Tren Krom's island was located at the end of the western arm of the Matoran universe. It was the sixth and final island in a chain of islands starting in the north with Artakha and running south.7
Tren Krom knew that Mata Nui was the Matoran universe.8