The mind flayer life cycle is a closely guarded secret that few nonillithids have become privy to. Illithids begin their lives as tiny tadpoles in a briny pool. To reach maturity, the tadpole undergoes a transformative process called ceremorphosis. The process begins when a tadpole is inserted into the brain case of a host human (usually via the ear canal). The tadpole burrows into its victim’s brain, quickly consuming much of the gray matter and replacing the consumed brain with its own squalid tissue. In effect, the tadpole melds with the uneaten lower brain stem of the victim, wiping out all remnants of the personality and spirit of the host, while leaving the physical body alive and ready for habitation. Within days, additional morphological transformations complete the maturation process of an adult illithid.
Ceremorphosis completely replaces the original tissue ofthe victim with illithid tissue; when the transformation is complete, the original victim is dead, and no spell or power can reverse the process.
Humans are almost always used as hosts for tadpole implantation, because they are the only race that produces true illithids. The process also works on other kinds of humanoids, but it yields a half-illithid rather than an actual mind flayer. As in the case of the half-illithid lizardfolk described here, these creatures are all formidable in combat because they gain many of the parent mind flayer’s special attacks.
“Half-illithid” is an inherited template that can be added to any humanoid other than a human (referred to hereafter as the base creature). It uses all the base creature’s statistics and special abilities except as noted here.
Type: The creature’s type changes to aberration. It retains any subtypes it has.
Hit Dice: Change to d8.
Armor Class: Natural armor improves by +1.
Attacks: A half-illithid loses its bite attack (if the base creature has one), but gains four tentacle attacks, in addition to the base creature’s attacks (except for a bite).
Damage: If the base creature does not have tentacle attacks, use the appropriate damage value based on the half-illithid’s size (see the table below). Otherwise, use the value from the table or the base creatures damage, whichever is greater.
| Size | Tentacle Damage |
|---|---|
| Fine | — |
| Diminutive | 1 |
| Tiny | 1d2 |
| Small | 1d3 |
| Medium | 1d4 |
| Large | 1d6 |
| Huge | 1d8 |
| Gargantuan | 2d6 |
| Colossal | 2d8 |
Special Attacks: A half-illithid retains all the special attacks of the base creature. It gains the mind flayer special attacks of mind blast, improved grab, and extract, and may also have psionic powers.
Mind Blast (Sp): A half-illithid can use this attack once per day. It is a cone 40 feet long. Anyone caught in this cone must succeed on a Will save (DC 13 + half-illithid’s Int modifier) or be stunned for 1d4 rounds. This DC is listed in the half-illithid’s statistics block under Special Attacks.
Improved Grab (Ex): If a half-illithid hits an opponent that is its own size or smaller with a tentacle attack, it deals normal damage and attempts to start a grapple as a free action without provoking an attack of opportunity. If it gets a hold, it attaches the tentacle to the opponent’s head. After a successful grab, the half-illithid can try to attach its remaining tentacles with a single grapple check. The opponent can escape with a single successful grapple check or Escape Artist check, but the half-illithid gets a +2 circumstance bonus for every tentacle that was attached at the beginning of the opponent’s turn.
Extract (Ex): A half-illithid that successfully maintains its hold with all four tentacles for 1 full round automatically extracts the opponent’s brain at the beginning of its next turn, instantly killing that creature.
Psionics (Sp): A half-illithid with Intelligence or Wisdom of 8 or higher (after the ability score adjustments noted below) gains psionic abilities. These abilities are as spells cast by an 8th-level sorcerer (save DC 13 + spell level). The table below lists the abilities available according to the Hit Dice of the half-illithid. These abilities are cumulative; a half-illithid with 3 HD can use detect thoughts as well as suggestion.
| HD | Psionic Abilities |
|---|---|
| 1–2 | Detect thoughts 3/day |
| 3–4 | Suggestion 3/day |
| 5–6 | Levitate 3/day |
| 7+ | Charm monster 1/day |
Special Qualities: A half-illithid has all the special qualities of the base creature and also gains the qualities noted below.
Darkvision (Ex): A half-illithid has darkvision with a range of 60 feet (or as the base creature, whichever is better).
Spell Resistance (Ex): A half-illithid has spell resistance equal to 10 + its HD.
Telepathy (Su): A half-illithid can communicate with any creature within 100 feet that has a language. See Telepathy.
Abilities: Increase from the base creature as follows: Int +4, Wis +4, Cha +4.
Environment: Same as the base creature and any underground.
Organization: Same as the base creature (to a maximum of about 10 creatures) or cult (6–10 plus 3–5 mind flayers).
Challenge Rating: Same as the base creature +3.
Alignment: Usually evil (any).
Level Adjustment: +5.
Half-illithid humanoids often have a character class. Their favored class is sorcerer. (If you are using the Expanded Psionics Handbook, their favored class is psion instead.)
Source: Fiend Folio, page 91. Changes applied as per the D&D® v.3.5 Accessory Update.