Gore Nest

Gore Nests are sessile demonic creatures created as a sort of living portal generator, fueled by the victims of invading demons. They are created wherever the demons invade, and do not appear to be native to Hell.

Biology
Gore Nests are reddish, sessile organisms somewhat resembling a fleshy dinosaur-like head facing upwards, appearing to grow out of the ground like some sort of plant. While Gore Nests have mouths lined with sharp teeth, they are incapable of moving their mouths or of eating, or of any movement at all. On their right side is a growth resembling some sort of blister, appearing to be the "eye" of the Gore Nest at first glance, is actually a covering for the only known organ of the Gore Nests, their hearts, which keep the Nests alive. Despite not showing any sign of sapience or intelligence, or the ability to move their mouths, Gore Nests are known to whisper loudly in a demonic tongue. Gore Nests are not natural organisms, but a living Hell portal generator that can allow more demons to enter the Multiverse, created by rituals conducted with the remains of the victims of demons, growing from the corpses and using the biomass as a sort of "soil." The portal in question is spherical and red in color, located above the mouth of the Gore Nest, although certain Gore Nests have been seen with different colors for their bodies and portals. Gore Nests appear to generate these portals through electromagnetic frequencies powerful enough produce inverse quantum fields, which rip a hole in space-time. Gore Nests can be destroyed by having their hearts ripped out, although harming the Nest or other demons around it will summon another horde of demons from Hell. Gore Nests, if left undisturbed for a long enough period of time, and presumably "fed" more blood and biomass, will grow exponentially, creating a massive "Hellgrowth" and growing large enough to engulf entire multi-story complexes and start a form of terraforming, pumping out toxins and making the environment of what worlds the demons invade better resemble Hell. Such a Gore Nest, known as a Super Gore Nest, no longer resemble a saurian head, but rather, a massive tower of biomass, with many mouths, tendrils, and bone-like structures, as if becoming an asymmetrical gargantuan organism, although they remain sessile. Their portals will also grow exponentially, becoming more orange in color and able to summon massive armies of demons instead of small hordes. While they become incredibly large, they can still be killed by destroying their hearts, although their hearts also grow very large and thus become far more difficult to destroy. Unlike regular Gore Nests, which explode a few seconds after their hearts are destroyed, Super Gore Nests will collapse after about a minute and a half after their heart is destroyed, which also halts the Hellgrowth they spawn.

History
On whatever world the demons invaded, they would gather the fresh bodies of their victims to conduct rituals that would make the biomass into Gore Nests. The Gore Nests would start siphoning more demons to the invasion site, bolstering their numbers unless destroyed. When the resurrected Spider Mastermind invaded Mars, many Gore Nests were created across the Union Aerospace Corporation (UAC) complexes, bolstering the number of demons present in the base and spreading Hellgrowths. However, these Nests were all destroyed by the Doom Slayer, who ended the invasion. In the subsequent Maykr-led invasion of Earth, more Gore Nests were created across the planet, with the first Gore Nest being constructed somewhere in central Europe, where the invasion began. This Gore Nest grew exponentially as the continent was overrun, becoming a massive Super Gore Nest, bringing over entire legions of demons. The last source of Human resistance, the Armored Response Coalition (ARC), led an assault on the Super Gore Nest with ground troops and naval forces, but were unable to break the demonic lines, forced to retreat after very heavy casualties. Some troops who got into the building where the Gore Nest was growing from broadcasted information on it to the ARC command, who recorded it as the largest Gore Nest ever seen. Some time later, when the ARC faced collapse, the Doom Slayer, previously banished to an unknown region of space after killing the Spider Mastermind for good, returned to Earth in an Argenta space station.