The Soul Worms are an evil inter-dimensional race of conquerors and raiders in the Palladium Rifts Megaverse roleplaying universe. Beings whom are malevolent and sadistic, enslavers and manipulators.
They used to serve a powerful alien intelligence who ruled over hundreds of worlds thousands of years ago. One day, their master was suddenly gone. There were no indications as to whether it had been destroyed by an enemy or if it had left and would return. It's disappearance left them vulnerable to the numerous enemies it had earned over time. Said enemies (including the Splugorth) took advantage of the situation and invaded their master's former territories. Approximately 9/10s of the Soul Worms perished, either at the hands of the invaders or of their former master's slaves who rose up against the Soul Worms. The remnants scattered across the Megaverse.
Only a couple thousand Soul Worms remain. Some have established their own dimensional kingdoms. Others have become the leaders of dimensional raiders. Some now wander the Megaverse. Others serve evil gods or powerful demon lords.
One of these Soul Worms is Inix who ruled a trans-dimensional city (known as Cibola) in a pocket dimension for thousands of years. It was one of the Megaverse's trading posts, with portals to other dimenions. One day they noticed that the pocket dimension had become destabilized and it was steadily collapsing. Inix learned that the cause of the disruption was the planet Earth (a world undergoing a great cataclysm due to the eruption or reawakening of its ley lines).
Upon discovering that the Earth had become one of the few Megaversal nexuses, he relocated Cibola to Earth. Now his trans-dimensional trading post is in South America, and is one of only two such trans-dimensional trading post on Earth (the other one being Atlantis, ruled by a Splugorth). It has a population of over a million and it's most important site is the "Tower of a Hundred Gates" (actually only 40+ permanent portals to other dimensions).
Soul Worms are larva-like fleshy beings that have a huge cyclopean eye in the head (one end of their worm-like body), which is surrounded by a dozen tentacles. When it comes to their dimensions, they range in size from 5 to 7 ft in height and 25 to 30 ft in length. Soul Worms live for at least thousands of years (e.g. Inix).
Soul Worms have a variety of enhanced senses (e.g. night vision). They are also have super strength and can regenerate. What they are known for is draining the life force and memories of their victims. When doing so they cannot take any other action, having to focus on the target so their victims are prisoners and slaves. Most Soul Worms become addicted to this and perform it at least once a week. They also have psionic abilities and the ability to use magic. Soul Worms are so resilient that they can survive a 3.8 Megaton nuke (though they would be gravely wounded).