Apothicon

The Apothicons are a malevolent race of inter-dimensional beings that were birthed at the beginning of time. Initially part of the race of benevolent Keepers, the Apothicons split off into a corrupted version of their former kind.

Biology
Due to their nature, there are various different subspecies of Apothicons, with their features, sizes, and structures varying from one another, however there seems to be a consistency regarding their sharp teeth and various tentacle-like appendages with most Apothicons.

Culture and Society
The Apothicons do not have a true "society", with all of their effort being spent into both consuming other dimensions and returning to their former home of Agartha. The Apothicons are linked together through a collective hivemind, sharing the same thoughts and experiences. However, some, like the Shadowman, appear to be able to feign independence and retain their own personalities and experiences despite still being part of the overall Apothicon hivemind. However, it is implied that they worship the various "Elder Gods" of the Apothicons, due to their title, and thus can be stated to have a form of religious system.

History
At the beginning of time, there were only the Keepers, who were the creators and caretakers of creation. However, a group of Keepers led by the individual who would soon become known as "The Shadowman" ventured into a dimension of pure corruption and evil known as the Dark Aether. They soon discovered an element known as Divinium that corrupted their minds and spirits. They soon declared war against that uncorrupted kin, beginning the War of Agartha, which the Keepers eventually won. The Apothicons were banished to the Dark Aether that had corrupted them, where they transformed even further into monstrous abominations.

At some point, the Apothicons almost escaped the Dark Aether and had a presence on medieval Earth. However, they were driven back shortly afterwards by an alliance of Keepers and Human knights. A large pyramid-like artefact was left behind, but the Keepers relocated it to Earth's moon to prevent its further usage. Centuries later, the Apothicons attempted to escape again by launching Divinium-infused meteors across the multiverse. Those that landed on Earth were discovered by the Germans during World War II, leading to the formation of the research group 935. The purpose of their research was to create new weapons powered by Divinium, which they referred to as Element 115. During this time, more Divinium meteorites were discovered by the Japanese and later the Americans, resulting in the establishments of Division 9 and Broken Arrow respectively. However, it quickly became apparent that Humans exposed to Divinium would be corrupted by it, becoming Zombies much like how the corrupted Keepers became the Apothicons.

During development of a 115-powered teleportation system, Dr. Edward Richtofen of group 935 was accidentally sent to the moon and discovered the pyramid, through which he was contacted by the Apothicons. As 935's research expanded, Richtofen was gradually driven mad by the voices in his head, intent on ending the world at their behest. To this end, he sought to dispose of his colleague, Dr. Ludwig Maxis, via the teleporter, using his daughter Samantha as bait. While Maxis had disappeared to an unknown location, Samantha ended up in 935's moon base, where she found the pyramid. Upon entering it, she became possessed by the Apothicons, who used her to assume control of the Zombies and other corrupted creatures on Earth, resulting in a Zombie apocalypse across Germany and Japan. Realising the Zombies were influenced by Samantha, as well as her likely pursuit of revenge for his betrayal, Richtofen released three of his test subjects, soldiers from America (Tank Dempsey), Russia (Nikolai Belinksi) and Japan (Takei Masaki) and enlisted their aid in neautralising the Zombie hordes. Their struggle for survival resulted in a teleporter malfunction that sent the group forward in time to the 1960s.

As the Zombies followed them through to the future, the team embarked on a worldwide mission to acquire components for a device Richtofen claimed would stop Samantha. Once all the components had been found, they travelled to the moon and used the device to remove Samantha from the pyramid, freeing her from the Apothicons' influence. However, Richtofen revealed his true colours at this point, taking Samantha's place and assuming control of the corrupted hordes. At this point, Dr. Maxis revealed himself and launched the moon base's nuclear arsenal at Earth, shattering the planet into a blasted wasteland and denying Richtofen and the Apothicons their victory. However, Maxis himself had been corrupted as well, as he manipulates four survivors on Earth into allowing him to replace Maxis, before casting Samantha out of reality.

Samantha found herself in Agartha, the home dimension of the Keepers. Determined to stop the Apothicons, she contaced alternate versions Dempsey, Nikolai, Takeo and Richtofen in a parallel universe (the primis timeline) where the Germans discovered Element 115 in the first world war rather than the second. Convincing them to open the way to Agartha and save their version of Maxis, they are introduced to a Keeper, assuming the form of a human called Dr. Monty, who introduces a plan on how to prevent the Apothicons from escaping the Dark Aether. This plan involved acquiring a Keeper artefact known as the Summoning Key and eliminating themselves in the original universe (ultimis timeline) in order to use their souls to stabilise the multiverse and seal the Dark Aether. The Summoning Key was found in Morg City, where the Apothicon Emissary corrupted the population and used the resulting Zombies and other lesser Apothicons to trick four survivors into opening the Dark Aether. When the Shadowman's true nature was discovered, the group joined forces with the Keepers and imprisoned him within the Key, only for it to be stolen by the Primis timeline's Richtofen.

With the Summoning Key in their possession, the team travelled to the moment Richtofen betrayed Maxis, where the mad scientist was executed by his younger, sane self. With Richtofen's death, the Ultimis timeline fractured, forcing the team to travel between timelines to locate and kill their older selves, all the while facing the endless armies of the Apothicon's corrupted monsters. Eventually, they acquired all the souls they needed and returned to Agartha to complete Monty's plan. However, Maxis is tricked into releasing the Shadowman from the Summoning Key, resulting in the Apothicons finally escaping the Dark Aether and invading Agartha with Zombies and other corrupted creatures summoned from the other broken realities. Recognising that the destruction of the Multiverse was imminent, the team fought and killed the Shadowman before Maxis used the Summoning Key to banish the remaining Apothicons back to the Dark Aether. Afterwards, Monty decided that in order to maintain multiversal stability, as well as to break the cycle to ensure the Apothicons would never return, he sent Dempsey, Nikolai, Takeo and Richtofen back to medieval times, making them the knights who drove back the Apothicons during their first incursion on Earth.

Games

 * Call of Duty: Black Ops (alluded to)
 * Call of Duty: Black Ops III
 * Call of Duty: Black Ops 4

Comics

 * Call of Duty: Zombies (Dark Horse)