Scuttlegeist (5e Creature)
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Small undead, unaligned
Damage Resistances acid, cold, fire, lightning, thunder
Ethereal Sight. The scuttlegeist can see 60 feet into the Ethereal Plane when it is on the Material Plane, and vice versa.
Illumination. The scuttlegeist sheds dim light in a 20 foot radius.
Incorporeal Movement. The scuttlegeist can move through other creatures and objects as if they were difficult terrain. It takes 5 (1d10) force damage if it ends its turn inside an object.
Slime Trail. When the scuttlegeist move over terrain while on the Ethereal Plane, it can choose to release slime in the corresponding space on the Material Plane. This space becomes difficult terrain for 1 hour, or until the slime is washed away with large quantities of water.
Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 16 (4d6 + 2) piercing damage.
Etherealness. The scuttlegeist enters the Ethereal Plane from the Material Plane, or vice versa. It is visible on the Material Plane while it is in the Border Ethereal, and vice versa, yet it can't affect or be affected by anything on the other plane.
The ghost of a long-dead predator. The scuttlegeist is a speedy, darkness-loving omnivore; it is highly attracted to small objects, especially metallic in nature, and will steal almost anything it can stash in the small holes it excavates with its jaws. Its tendency to leave other objects in place of those it pilfers may be mistaken for a well-intentioned "trade," but its aim is seemingly more to taunt and unnerve its targets.