- "You can hear us. We can feel you. We... crave destruction. But pain... we are in great pain!"
- — Apothicon Blood
The Apothicons are a group of Keepers that were corrupted by the Dark Aether, with their only goal of wreaking havoc across all of creation. The Shadowman is a known Apothicon. Many weapons, such as the Apothicon Servant and Apothicon Swords are named after them. The Apothicons were also the creators of the Aether pyramid or MPD. They are main antagonists of the Zombies map Revelations, and, by extension, the entire Zombies storyline.
The Apothicons were originally part of the ancient order of the Keepers residing in Agartha, but upon contact with the energy of the Dark Aether, part of the Keepers were corrupted and betrayed their brethren. After a war between the two forces, the corrupted Keepers were eventually defeated, and what was left of them was banished into the Dark Aether beneath creation for all eternity.
After spending time trapped in the Dark Aether, the corrupted Ancients morphed into hideous creatures that shared little resemblance to their former species. During the Middle Ages, the Apothicons managed to escape their prison and invaded Earth, but were fended off again by the Keepers, this time with the help of human knights and were sealed once again within the Dark Aether.  Soon after, they began planting Divinium, better known as Element 115, in various dimensions, with one meteor landing in the Rising Sun facility in the original timeline, and another landing in the trenches of World War I France in the altered timeline.
In the Original Timeline, a corpse of an Apothicon Elder God was discovered by the Ascension Group at the bottom of the ocean, where it's blood was thereafter captured and brought aboard the Soviet ship known as the Tugarin. The Ascension Group experimented with the blood, such as injecting injured monkeys with the blood, until the Blood eventually broke out of containment and started an outbreak, killing many of the personnel and turning the rest into zombies.
In Dimension 63 in Morg City, an emissary of the Apothicons managed to trick four cursed souls into releasing the Apothicons in their dimension using the Summoning Key, but the creatures were stopped with the help of the Keepers and the Shadow Man gets trapped inside the Key.
In the ending cutscene for Revelations, after the Shadow Man is killed, Maxis and Sophia sacrifice themselves to banish the remaining Apothicons from their universe. It is unknown where the Apothicons went or what their ultimate fate is, however Monty states that they are gone forever.
In another cycle, the Shadowman manipulates the Warden of Alcatraz to imprison four mobsters, Albert Arlington, Salvatore DeLuca, Billy Handsome, and Finn O'Leary in Purgatory. He later instructs the Warden to trap Primis in Purgatory in order to gain Richtofen's blood, so he could use it to open a gateway to Agartha. This plan fails, and the Apothicons remain trapped within the Dark Aether, with the Shadowman residing in the Summoning Key.
- "Leesanatahn lu ahm... we now speak the tongue which is forbidden. Bring us the Seal of Duality... that we may cleave to our sworn enemy. We must restore that which was separated."
- — Apothicon Blood
Shortly after gaining the Elemental Shard, Ultimis Richtofen (who became Undead Richtofen) awoke Victis from their cryosleep and sent them to craft the Agarthan Device. In Victis' quest to gain the Device, they were assisted by the blood of an Apothicon Elder God. In doing so, the Seal of Duality resolved the differences between the Keepers and the Apothicons, merging them back into one species within the Aether again.
After Primis and Ultimis gained the Agarthan Device from Victis, they used it to destroy the Summoning Key, which destroyed the Shadowman and all those still within it. After the multiverse was plunged in to the Dark Aether, the Apothicons, alongside their formerly Keeper brethren and Element 115, were seemingly trapped with no way out.
- Shadowman's subspecies
- Insanity Elementals
- Li'l Arnies
- Apothicon Elder Gods
- Despite being a Keeper, Dr. Monty's true form bears an extreme resemblance to that of an Apothicon, specifically that of the Shadowman's subspecies.
- In Tag der Toten, it is revealed that this is due to the fact that, like the Apothicons, Doctor Monty was also corrupted by the Dark Aether.