Trappers know when prey draws near, so explore ruins and dungeons with equal wariness. For dumb beasts, they know very well what treasure is, what treasure chests are, and know these lure the likes of us –Volo
TRAPPER
A trapper is a manta-like creature that lurks in subterranean and natural environments. It can change the color and texture of its tough, outward-facing side to help it blend in with its surroundings, while its soft, inward-facing side clings to the floor, wall, or ceiling in its hunting territory. It remains motionless as it waits for prey to come close. When a target is within its reach, it peels itself away from the surface and wraps around its prey, crushing, smothering, and then digesting it.
Versatile Camouflage. A trapper can alter the color and texture of its outer side to match its surroundings. It can blend in with any surface made of stone, earth, or wood, masking its presence to any but the most rigorous scrutiny. It can't change its texture to that of a grassy or snow-covered surface, but it can change its color to match and then conceal itself under a thin layer of vegetation or actual snow.
Stationary Hunters. A trapper needs to eat about a halfling-sized meal once a week to remain sated. It is content to stay in one place, given a steady supply of food, and thus trappers are a threat along any well-traveled dungeon corridor and on routes through the wilderness that see a lot of traffic. When prey is scarce, a trapper enters a state of hibernation that can last for months, though it is still aware when prey comes near. A trapper on the verge of starvation might defy its instincts and begin creeping along, abandoning its old territory in search of better hunting.
Beware of Leftovers. When its prey is dead, a trapper dissolves and absorbs the fleshy parts, leaving a scattering of bones, metal, treasure, and other indigestible bits in the place where the creature had been. A trapper that lurks on the floor of its hunting grounds can cover these remains with own body, making them look like irregularities in the surface. The creature might also attach itself to a wall or a ceiling close to a recent kill, effectively using the remnants as bait: a creature that stops to investigate the bones for valuables stands a good chance of becoming the trapper's next meal.