Cacodemon

"They float in the air, belch ball-lightning, and boast one Hell of a big mouth. You're toast if you get too close to these monstrosities."

- DooM II: Hell on Earth instruction manual

"Sweet Christmas! Big-mouthed floating thingies! It's always something!"

- Doomguy, Doom Comic

The Cacodemons (also nicknamed "Pumpkins" and "big-mouthed floating thingies") are a species of psionic demons that are generally spherical in nature and capable of firing out energetic orbs at opponents. They were first witnessed by the UAC during the first invasion of Mars and Phobos. Many varieties of Cacodemon are known to exist, including two known subspecies - the Malwrath and the Wretched.

Biology
Cacodemons bear a spherical shape, entirely red in color, with six large horns around its head, a single green eye, and a large, fanged, perpetually grinning mouth. They have two orifices on their lower backsides that serve an unknown purpose, and what appear to be short, curled up tentacles on their undersides. Their bodies are capable of taking considerable amounts of damage, and they can generate and fire balls of plasma from their mouths. Cacodemons and their subspecies are capable of flight and energy ball generation. Their exact mechanism of flight is unknown, but it could either be the result of psionic abilities or being filled with hot hydrogen gas. A six-eyed variant of Cacodemons exists, which is grey-skinned and appears to have an exposed brain atop its head. In addition, it has an array of long, thin tentacles that hang down from its underside. While faster, it flies more erratically, and is weaker than the original breed. Another variant of Cacodemons, while resembling the original breed, appears to bear reddish-pink spiked armor on the upper half of its body, and has a far larger maw in a perpetual frown with two large upper fangs and a split jaw. Its eye lacks a pupil, and a bulge is visible on its underside. In addition, it bears four stunted limbs, which appear to be two arms and two legs, implying that the Cacodemons evolved from a land-based species. Another armored variant, possibly a more evolved version of the original armored strain, bears greater resemblance to the original breed of Cacodemons. This variant regained the predominantly red color scheme, and regained a pupil in its eye. Its limbs appear somewhat more developed, but still stunted and useless. The original and second armored breeds of Cacodemons are known to have blue blood. Armored Cacodemons are known to explode if their eye is torn out of their body, possibly supporting the theory of being filled with some sort of gas in order to fly. It is possible that the Cacodemons evolved from a now-extinct species of cyclopedic Hell Titans, or had their physiology otherwise influenced by them, as they bear some resemblance to the Titans, but any relation remains unknown. Cacodemons are devoid of major cognitive abilities and have very little intelligence, being driven by nothing more than the desire to feed. They will aimlessly wander unless directed to a location by demonic commanders such as the acting Dark Lord, and will relentlessly chase down any potential meals, including Humans.

History
The Cacodemons came from a demonic dimension called Hell. Throughout an unknown period of time, some subspecies of Cacodemons arose, and were used in interdimensional invasions, often fighting a race known as the Argenta, who were led by the Order of the Night Sentinels. The Argenta priests turned against the rest of the Argenta, siding with the Maykrs, who struck a deal with Hell for their mutual benefit. The Night Sentinels, along with their champion, an unnamed Human known only as the Doom Slayer, were trapped in Hell, where Cacodemons and other demons launched a relentless assault on them. Only the Doom Slayer survived, and continued to fight demons for eons, until he was finally locked away in a tomb on the surface of Mars within an unknown universe. In the future, when Union Aerospace Corporation (UAC) scientists were experimenting with teleportation technology on Phobos, they accidentally opened a rift to Hell. This caused a whole manner of demonic forces, including Cacodemons, to come through the portal onto Mars' moons and the other bases. The demons brought destruction on the UAC bases and killed or possessed many UAC personnel, although the invasion was stopped by a lone marine who killed the commanding Cyberdemon and Spider Mastermind. Not too much later, they made their way to Earth to continue their attack there. It was here that the single hero, the marine, slaughtered the demon hordes, including Cacodemons, and later managed to close the rift between the dimension of Hell and the Earth itself, sealing surviving Cacodemons away in Hell. The corpses of Cacodemons left on the Martian moons would later be revived by the Mother of All Demons, some being combined with biological material from Pain Elementals while others were made into new two-mouthed Pain Elementals, only for the marine to destroy them again. The marine then voluntarily remained in Hell to put down its threat forever, fighting hordes of demons alone, somehow going back in time and across dimensions, eventually becoming the immortal superhuman known as the Doom Slayer, the very one who had fought demons over eons. Some time in the future, in what appears to be another universe, a six eyed subspecies of Cacodemons were among an invasion force that attacked a UAC Mars base, brought over by a human cultist named Dr. Betruger. An unnamed UAC Marine fought his way through the Cacodemons and other demons to Hell, killing their Cyberdemon and stopping the invasion. At another point in the future, in what could be the same universe, armored Cacodemons were brought over to Mars by a growing faction of cultists within the UAC, led by Dr. Olivia Pierce. When the demons launched another invasion of Mars, the Doom Slayer was woken up, as the universe he was held in was the very one being invaded. Retrieving his armor and weapons, the Doom Slayer eventually fought Cacodemons, killing them and other demons, eventually killing the Spider Mastermind and stopping the invasion. Years later, in the same universe, a demonic invasion of Earth was launched at the order of the Khan Maykr, and Doom Slayer, who had been banished out to unknown regions of space at the end of the previous invasion, returned in an Argenta space station to combat the demons once more. A seemingly more evolved strain of armored Cacodemons were used, who fought alongside other demons against the Armored Response Coalition (ARC), Earth's current defense force, and UAC security forces not loyal to the cultists. Many were killed in Slayer's rampage throughout Hell, Earth, Mars, and Urdak. All Cacodemons remaining on Earth were killed or otherwise banished after the death of the Icon of Sin. Slayer then utilized ARC resources to retrieve the life sphere of the Dark Lord in order to destroy it, killing more Cacodemons along the way.