Planar Bestiary
A mask made of whorled shell with a strange light leaking from its mouth doesn't seem too dangerous. Until it begins to absorb people into a personal dimension where a much larger and more dangerous skein hunts. Hard shell protects the true skein's large bulk. Massive tentacles protrude from the front, surrounding a beaked mouth. The creature's armored shell includes the same pattern as the mask-shaped façade first encountered.
A roving skein exists in a personally generated dimension, but presents a simple mask to the outside world: their mask lure. Unless and until the mask lure begins to move under its own power as an animated object, most creatures probably mistake it for a regular mask.
A masked skein's personal dimension is a poor copy of the surroundings where their first mask lure was exuded, which means it could appear as countryside, a series of subterranean tunnels, an urban area, a forest, or something else. However, except for plants, insects, and any previously trapped creatures still alive within the artificial dimension, no other living things are present. In addition to other obvious differences, the dimension is usually no larger than a very long distance across.
If a skein’s mask lure is destroyed, the masked skein themself remains safe within their personal dimension.
Motive: Hungers for flesh
Environment: Anywhere in the multiverse, sometimes allied with another creature wearing the mask
Health: 15
Damage Inflicted: Moderate wound (5 points)
Armor: 3
Movement: Short
Modifications: Perception as level 6
Combat: The skein—which is hidden in another dimension—uses their mask lure to hunt prey in a standard plane of existence. The mask lure can affect one creature within immediate range with a non-consensual teleport about once each minute. If the creature fails an Intellect defense task, they're pulled into the masked skein's personal dimension.
Prey pulled into the skein's dimension appear next to the real skein. The skein attacks twice each round with their tentacles.
About once each minute, the skein can release an electrical discharge affecting foes they choose who are trapped within their dimension that fail a Speed defense task, inflicting 10 points of damage, or 4 points even with a successful defense task.
Escaping a skein's personal dimension requires killing the skein or using magic that allows planar travel. If the skein is killed, they and any trapped creatures and objects are expelled next to the mask lure, now nothing more than a weird mask made of horn.
Interaction: Masked skeins are intelligent, but they view all other living things, including intelligent ones, as food. Sometimes a masked skein communicates via telepathy but negotiating with one requires that they be fed something big for their trouble.
Use: The mask-shaped façade is sometimes encountered while worn by another creature, one who has proven themself willing to protect the lure and wear it so the skein looking out from behind the mask's eyes can feed on select targets.
Loot: Objects expelled from a defeated skein's personal dimension sometimes include coins equivalent to an expensive item (a few hundred gold coins) and perhaps a cypher or two, such as a pearl that tells the user a secret, or a shock attack shortsword.
GM intrusion: Another creature—perhaps a devil—is already hiding in the masked skein’s personal dimension. Allied with the masked skein, they also attack the character pulled into the dimension.