Cthul¶
"Delusion is the preferred state for a target whose brain a Cthul is about to consume, as the target may believe they are receiving some wanted attention, while in fact they are being eaten alive." — Cthul Overview (S517)
Contested
This page is named in the open question Cthul and Illithid. The Cthul of the Sancturi-era sources and the Illithids of the oldest archive may be the same creature under two names with two origins; the page treats the Illithids under Earlier accounts and does not rule.
The Cthul (Ka'Thool) are brain-eating parasites with tremendous psionic power, the best-known of the Dread and the one family that walks among mortals wearing their shape. "A Cthul is normally a humanoid creature with tremendous psionic abilities. They are actually a parasite that invades other organism's brains and consumes it while taking over control of their host's body. Their diet likewise consists entirely of brain matter of sentient creatures. The more intelligent the meal, the better" (S517). They are Outsiders who have "mastered the traversal of the Void" and "set up outposts" on Terrun (S001), and in the rune-lore of the Dread they are "an ancient family of organisms whose origins are uncertain … one of the most prolific Dread Races" (S257).
Also called: Ka'Thool (S517); Cthulic, of their works and powers (S257); possibly Illithids or Mind Flayers (S525, see below).
Form¶
"When a Cthul takes over a host, their brain is consumed entirely and tentacles will grow out of the orifices that once were the mouth, ears and eyes (and any other available orifices around the brain-cavity). These tentacles acts as the Cthul's sensory input (sound, touch, smell, taste and psionic sight) and grow to be 2-3 feet long. These tentacles are also used to feed and consume brain matter" (S517). "In form, most Cthulic creatures have tentacles" (S257). The tentacles of the Cthul that reach through a Zone of Dread come in four kinds: a "thick blood red tentacle" that blights, a "thick purplish black tentacle" that rots, "a very large and thick dark green and brown tentacle" that crushes, and "a thin long white rubbery tentacle," the mindeater, that drains reason, intellect and will until the mind collapses (S257).
"A Cthul gains all of the physical attributes and abilities of their host, including their spellcasting and innate magical abilities. Spellcasting can be useful but is seen by most Cthul to be more primitive and less powerful than their psionics" (S517).
Psionic sight and powers¶
"A Cthul can see psionically and does not have sight the way that most other living creatures do. Their 'psionic sight' is exceptionally good and is not affected by things like obscurement or darkness. Cthuls see in a 360 deg radius and can see through any known objects within their range. When not concentrating, a Cthul can sense everything within 200 feet, when concentrating it can be up to a mile" (S517).
"Cthuls are strongly attuned to Domination typed Psionics" (S257). Every Cthul holds up a constant psionic shield against magic and other minds; it can blast a cone of minds into stupor; it can dominate a single victim, and a victim who fails to shake free often enough "become[s] a Thrall, permanently dominated by the Cthul. A Cthul may control any number of Thralls, but can only have one dominated target (non-Thrall) at a time" (S517). Its subtlest power is delusion, "a complete illusion that alters the target's entire perception of reality. The Cthul may appear as the target's best friend, while their best friend may now look like the Cthul. A fiery pit may appear as an inviting pool … The delusion is so complete that damage is not felt and what looks and feels pleasant, may in fact be harmful." Those who know they face Cthuls "may be aware they are under a delusion, but translating the elements of the delusion back to reality is still impossible" (S517). The Cthul's psionics are counted among the Elder magics of Terrun (Elder Magic); the rules of its powers are not repeated here.
Reproduction and hosts¶
"Cthul's reproduce by produce spawns of larvae 2-3 times in their lifetime. These larvae are normally left to develop over a period of many years in a pool. Once fully grown, potential hosts are placed in the pool and the larvae compete with one another to take over the host. The larvae which successfully infect hosts survive, while the those that did not are killed. Normally, only approximately 20% of all Cthul larvae survive to become adult Cthul's due to this selection process. The process of fully infecting a host takes only about 60 seconds. It is unusual, but not impossible for a Cthul to change hosts. It is a very dangerous transition as a Cthul is very weak and vulnerable without their host. The most powerful Cthul often upgrade their host to larger and stronger creatures such as Ogres, Drakes, Dragons and Giants" (S517). A Cthul body may itself be taken by a demon: the Fourth Age reference lists the Cthul among the Outsider hosts a demon can possess (S331).
Elder Brains¶
The Cthul of a region answer to an Elder Brain. In the Sancturi campaign an "Elder Brain (Cthul) controls large area. Thralls and a few flayers" in the Underdark (S199, S200). One "Cthul Elder Brain" was "scheming to use an Eldritch as a host for its Cthuls" and had "developed a new kind of larvae .. which is capable of controlling multiple hosts (but only one at a time). Improves recovery times of Cthulic minds. (no need to respawn a larvae and rebind which can be a lengthy process)" (S194). An Elder Brain reached into the mind of the companion Abither, whispering "The Asmodeans are near and seek what you possess! I will guide you to safety," meaning "to assimilate him (and enslave the group)" and to lead them "towards one of the Cthul's lairs. Underground. Will be honest until not … its a trap" (S198).
Gap
The sources never describe an Elder Brain's form, how one arises from ordinary Cthul, or how many Cthul one commands.
Origins¶
The Cthul's own origins are disputed in-world. "One of the Elder races present on Terrun since the beginning, their origin is uncertain. Some scholars believe the Cthul's were created by the Einar, while others cite evidence that they may have travelled to Terrun from some other plane. Cthul's were initially loyal to the Gods of the Iztari and served as their Commanders, Heralds and Assistants. They developed very advanced techology, which has led many scholars to believe they are extra-planar travellers. While other scholars believe their technology was largely stolen from the Dwarrow and other races" (S517). The Nature of Magic lists the Cthul among the Elder races born in the Age of Titans, with "Eldritch, Giants, Faeries, Dinosaurs, Ventari, Dwarrow" (S208). The newest cosmology settles for the second school: Cthul, Tyrax and Abols are Outsiders who "visit Terrun, set up outposts and harvest Terrun's resources" (S001). The Dwarrow connection recurs in a hybrid "Dread(Cthul) & Dwarrow" creature that Khardas "tried to destroy" (S167). Among the Night Gods of the Fifth Age is Menae, "God of Illithids, the Insane" (Unaligned Gods) (S020).
Earlier accounts¶
The oldest family tree of the humanoid races has no Cthul but has Illithids: "born of a forbidden union between Ventari and some ancient and forgotten race, the Illithids became the bane of all civilized creatures. Extremely intelligent and vicious" (S525), a branch of the Ventari beside the Lothim and the Innus. The Cthul overview names the Illithid among its inspirations, and the register treats Illithids and Mind Flayers as names for the Cthul; the Sancturi session notes use "flayers" for the Elder Brain's servants (S199).
Gap
No source says in so many words that the Illithids and the Cthul are one race, and the two origins given, Ventari-born and Void-born, are not reconciled.
In Play¶
The Sancturi companions met Cthul of great power in the Underdark and the rifts (S185, S192, S193), fought "cthulic mindworm[s]" (S193), and crossed Cthul territory on every road west (S198). A Cthul's thralls are the first sign of one; the second is a friend who is suddenly very helpful. A Cthul fights at a distance through its powers and keeps its host out of reach, and without the host "a Cthul is very weak and vulnerable" (S517).