Vidius paused, listening. The others stopped at his signal as he squinted against the inky black of the cavern ahead; beyond the well of light from Galza’s softly glowing sword he could hear a sound, repetitive and sharp, growing nearer. Was it webbed feet slapping on the stone? Dozens of them at least. He signaled the others back, but the sound was accelerating closer, the slapping now coming impossibly fast. He got his first glimpse of the source in the blue light and turned in a panic to run.
Too late. The ball did not quite reach the walls on either side, but the arms protruding from it did. Soon they were all tumbling wildly, bashing against the wall, held by strong arms on the sides of the massive ball as it continued to hurtle down the cavern.
The Hectarm is a foul creation of magical psuedoscience. The large central ball is surfaced with a patchwork of skin stretched over a mass of muscle and bone (mostly rib cages and shoulder blades). Beneath this exterior layer is a massive conglomerate of brain matter tortured together by the maker of the Hectarm. Protruding from the ball are what seem a hundred arms, all coordinated by the great brain. With no eyes or other sensory tools, the brain has a psionic awareness of the space nearby, along with the feeling of each of the arms.
The Hectarm is heavy and the arms on the underside are not strong enough to hold it up. It is also uncomfortable to lie on top of these arms, so Hectarms move as constantly as they are able to prevent resting on any arm too long, lest they fall asleep and make movement awkward. Once a Hectarm gets moving with any kind of purpose, it gathers speed quickly as the arms pull it forward, reaching as high as 48 feet per second if it is unimpeded.
Hectarms are driven by two emotions: fear of additional pain and hate toward creatures that are free from the constant suffering it endures. To those ends, they will flee known danger, but rush against creatures hoping to grab, crush, and mangle them. If attacked, their arms attempt to grab weapons away and use them, if only briefly.