Parasite (Doom)

The parasites, also known as leeches, are an unnamed demonic parasitic species.

Biology
The parasites are small vermiform creatures, resembling a leech or worm, entirely black in color with a visibly segmented body and a mouth with four teeth arranged in a circular shape. The segment before their mouths bulge out, with an oblong green eye on opposite sides. They also have 6 smaller, circular glowing orifices on the segments after their eyes, possibly auxiliary eyes or a sort of biomechanical exhaust port, as parasites hold an incredible amount of Hell Essence within them, enough to power large biomechanical exoskeletons. Without an exoskeleton, they are extremely weak, unable to survive leaving Hell. What could possibly be a sub-species or related species of parasites called Hell Razers is known to infect unknown humanoid hosts, possibly Imps, Jekkadians, or Humans, turning them into armored energy-shooting beings. While the sapience of parasites is unknown, they are able to pilot humanoid mechs and will follow commands to protect a certain site or object. When threatened, parasites are known to growl.

History
Parasites arose in Hell at an unknown point in time, and at least three of them were given large, biomechanical exosuits to pilot from an unknown source, likely the Hell Priests or other high-ranking demons. These parasites became known as Hell Guards. After the fall of Argent D'Nur and the capture of the Elemental Wraiths, the Hell Guards were used to guard the Demonic Crucible, which served as a conduit for the Argent Energy the Well was generating. They were encountered in 2147 by UAC robot scout drones sent into Hell, destroying the scouts and ending the expedition. Their video footage, which was cut off by their destruction, revealed that the large humanoid bodies of the Hell Guards were simply biomechanical shells of bone and keratin, while the real Hell Guards were the parasites within. Other UAC expeditions, presumably made up of Lazarus Project cultists loyal to Olivia Pierce, were launched to retrieve the parasites, but all specimens they brought to Mars died due to being unable to withstand the passage between dimensions, although their remains were kept in stasis pods. When the Spider Mastermind launched an invasion of Mars, the Doom Slayer, previously brought to Mars, awoke and fought his way into Hell to cut off the Well's production of Argent Energy, confronting and battling the Hell Guards. While they fought with their suits and all their strength, the Doom Slayer killed all three of them, breaking their suits to get to the pilot parasites. No other parasite was seen by the Doom Slayer. When the first Dark Lord, Davoth, was killed, his death killing all demons outside of Hell, it was likely that almost all surviving parasites survived, as they did not venture outside of Hell on their own.

Appearances

 * Doom (2016)