Luther seems to be a regular male human in his early twenties at first, but he can transform his body parts into a mass of tentacles. His hair is white and only reaches about under his ears, which are pointed at the tips. His tongue is also a tentacle, and his eyes are a bright orange.
His skin is pale and he wears a black T-shirt with many tattoos on his arms and dark jeans. His true form, a mass of dark tentacles, has a skull for a face instead of a monstrous cephalopod limb. This is the skull of the original Luther, who was killed by a tentacle-monster and then had his identity assumed by it.
Born in 1899, Luther and his twin brother Gabriel were investigating the Arctic Ocean looking for cryptids that had been sighted there in 1920. Gabriel was much more scholarly and roped Luther into the mission, which was his first mistake. Luther saw an octopus and, thinking it's a cephalopod cryptid, attacked it. He was pulled under the water and saw the octopus be consumed by a much larger creature that seemed to only be composed of tentacles. Suddenly, he was impaled by a tentacle.
The monster, assuming Luther's identity, began to search for Gabriel for nearly a century, attempting to find the artifacts of immense power that Gabriel has procured. Along the way, he met the Demon who convinced him to go after the main characters.
The creature is greedy and wrathful, enjoying inflicting pain. He wants ultimate power, searching for a lost explorer to gain magical items. Luther enjoys hurting the main characters, and exhibits gluttony by eating live creatures. He is a terrifying monster who gives off an aura of uneasiness.