Gutworm (CR 1/8)
Tiny Outsider (Chaotic, Evil, Extraplanar, and Symbiont)
Alignment: Always chaotic evil
Initiative: -3 (Dex); Senses: darkvision 60 ft., Listen +6, and Spot +6
Languages: Telepathy to host
AC: 10 (+2 size, -3 Dex, +1 natural), touch 9, flat-footed 10
Hit Dice: 1d8+1 (5 hp)
Fort +3, Ref -1, Will +2
Speed: 5 ft.
Space: 2 1/2 ft./0 ft.
Base Attack +1; Grapple -10
Attack: -
Full Attack: -
Damage: -
Special Attacks: -
Abilities: Str 4, Dex 5, Con 12, Int 5, Wis 10, Cha 7 (Ego: 9)
Special Qualities: enhance Constitution, incite rage, infect, neutralize poison, outsider traits, symbiont traits
Feats: Alertness
Skills: Hide +9, Listen +6, Move Silently +1, and Spot +6
Advancement: -
Climate/Terrain: Any land and underground (Abyss)
Organization: Solitary (symbiont)
Treasure/Possessions: -
Source:
Fiend Folio
An Abyssal relative of the tapeworm, the gutworm is a vile fiend that lives in its host's digestive system. It appears as a 1-to-2-foot long segmented worm of deep purple color, dripping with thick yellowish slime. It has bulbous red eyes and a toothy maw. Unlike a tapeworm, it does not attach itself to the intestinal wall, but swims freely around within the digestive tract, creating an uncomfortable sensation in the host.
Gutworms do not speak, but they understand Abyssal.
Combat
Gutworms do not engage in combat.
Enhance Constitution (Ex): A creature with a gutworm symbiont gains a +2 inherent bonus to its Constitution score.
Incite Rage (Ex): At will, a gutworm can cause its host creature to enter a frenzied state identical to a barbarian's rage (+4 Strength, +4 Constitution, +2 morale bonus on Will saves, -2 AC penalty). The rage lasts 4 rounds, and the host is not fatigued afterward.
Infect (Ex): Gutworm eggs are often found in the polluted water of the Abyss and infect creatures that drink the water. A purify water spell does not remove the eggs from the water, although they die if left in pure water for one day. Once inside a host, the eggs hatch in 1d4 hours, and the spawn set about devouring one another until only one remains. A remove disease spell cast on the host kills a gutworm, but the host takes 4d6 points of damage from the creature's death throes. A creature with a gutworm must ear twice as much food as it normally requires each day, and must start making daily Constitution checks after only one day without food (instead of the normal three days). In addition, the host creature is fatigued after 8 hours of activity and takes a -4 penalty on the following checks and saves: Swim checks to resist subdual damage; Constitution checks to continue running, to avoid subdual damage from a forced march, to hold its breath, or to avoid subdual damage from starvation or thirst; and Fortitude saves to avoid subdual damage from hot or cold environments, or to resist damage from oxygen deprivation.
Neutralize Poison (Su): Once per day, a gutworm can negate any poison introduced into its host's body (not just ingested poisons), protecting its host from any ill effects.
Outsider Traits: A fiendish symbiont has darkvision (60-foot range). It cannot be raised or resurrected (though a wish or miracle spell can restore life).
Telepathy (Su): A fiendish symbiont can communicate telepathically with its host creature, if the host has a language.
Symbiont Traits: When joined with a host, a symbiont gains a number of benefits. It acts on its host's turn each round, regardless of its own initiative modifier. It is not flat-footed unless its host is, and it is aware of any danger its host is aware of.
A symbiont never takes damage from attacks directed at the host. Like a worn magic item, a symbiont is usually unaffected by spells that damage the host, but if the host rolls a 1 on its saving throw, the symbiont is one of the "items" that can be affected by the spell. A symbiont uses its host's base saving throw bonuses if they are better than its own.
Share Spells (Su): Any spell the host creature casts on itself automatically also affects the symbiont. Additionally, the host may cast a spell with a target of "Self" on the symbiont instead of on itself. Likewise, a symbiont can choose to have any spell or spell-like ability it uses on itself also affect the host creature, and may cast a spell with a target of "Self" on its host instead of on itself. The host and symbiont can share spells even if the spells normally do not affect creatures of the host or symbiont's type. Spells targeted on the host by another spellcaster do not affect the symbiont, and vice versa.