Merlot

The Grimm are a superior species, fascinating in their biology, their unbridled, raw aggression and lack of sentience make them the perfect vessel.

Doctor Merlot is the main antagonist of the video game RWBY: Grimm Eclipse. He has yet to be mentioned or appear in the show itself.

Appearance
Merlot is an old man with one robotic, glowing red eye. He also has a robotic right arm with red inner circuits.

He has disheveled gray hair, a matching moustache and beard, and prominent eyebrows. He wears a gray jacket with a high collar and a red shirt underneath.

Background
Doctor Merlot was the founder of Merlot Industries, a research and development corporation based out of the ill-fated settlement at Mountain Glenn. At some point, Merlot gained an unhealthy obsession towards the creatures of Grimm, believing them to be a "superior species" due to their "unbridled raw aggression and lack of sentience". Said fascination led to him falling out of favor with Professor Ozpin.

Merlot was personally familiar with Ozpin, whom he called by the nickname "Oz". However, they were on bad terms, with Ozpin believing that the world would have been better off had he died in the disaster that he had caused. According to Ozpin, the other professors at Beacon Academy had a similarly low opinion of him.

Undaunted, the corporation began performing experiments on Grimm, research which Merlot believed was vital to the future of Remnant. However, when they began running out of specimens to experiment on, they started attracting Grimm to the city in order to acquire more, with disastrous results. After the fall of Mountain Glenn, Doctor Merlot was presumed dead.

Re-Emergence
However, Merlot in fact survived the destruction of Mountain Glenn, though he would later admit to Ozpin that its loss continued to upset him. He transferred his operation to a highly remote island at an unknown location, and continued his experiments at his new secret laboratory, creating new forms of mutant Grimm using his serum, a glowing green substance.

Years later, Team RWBY would lead an investigation of mutated Grimm traced back to Merlot Industries, eventually arriving on Merlot's island. His operations uncovered, Merlot reveals himself to the team as well as to Professor Ozpin, conversing with them remotely and taunting them. However, after Team RWBY infiltrates his laboratory and destroys a mutant Death Stalker, he self-destructs the laboratory.

After the destruction of his laboratory, his whereabouts and status are unknown.

Trivia

 * Merlot is a type of grape most notably used in making the red wine that shares its name.
 * The character of Doctor Merlot may allude to the science fiction novel The Island of Doctor Moreau by H. G. Wells. Apart from the similarity in name, the story features an eccentric doctor living on a remote island and performing morally questionable experiments on animals.
 * The song "Lusus Naturae" is presumably written from Merlot's perspective, and goes deeper into his motivations and obsession with the Grimm. The song is written and performed by Jeff Williams and plays over the credits of RWBY: Grimm Eclipse.