1st draft, not near finished yet, probably needs another racial ability or two. Assume a humanoid form, just because.
Cellochoroid
Cellochoroids aren't individuals. Instead, they are a mass of smaller fungi that have melded together to form a vaguely humanoid body. Apart, Cellochoroids appear as thick turquoise moss, usually in clusters roughly the size of a baseball, and possessing a similar intelligence. Together, their psychic abilities bind their minds and forms together into a sentient collective. Asexual, larger Cellochoroids shed off excess moss from the collective whole to "reproduce", with new Cellochoroids developing when enough accumulates in a small area. As such, "newborn" Cellochoroids are quite literally the children of all the adults in a colony.
Originally, Cellochoroids were simple, non-sentient fungi. The presence of the domes, and the heat they provided, encouraged their growth, while the domes' magical waste slowly mutated them into sentient beings when in large enough clusters.
Plant (psionic) type: Immune to sleep, stun, paralysis, polymorph, poison, crits, and mind-affecting (but see Redundant Sentience below).
+2 Int, -2 Dex: Cellochoroids aren't particularly mobile, but the combined intelligences inside a single body can provide great leaps of intuition.
Small size: +1 attack/AC, +4 Hide, 3/4 carrying capacity, etc.
20 ft. speed
Low-light vision
Naturally Psionic: Cellochoroids have 1 power point.
Fungal Sustenance (Ps): Cellochoroids can thrive and grow on heat alone. They can manifest Sustenance at will as a psi-like ability with a manifesting time of 1 hour, but only while they are near a heat source.
Modular Physiology (Ex): One clump of Cellochoroid is as good as another to an animate mass. A Cellochoroid can detach its body parts at will and without harming itself, but its Intelligence score decreases proportionally to the total mass lost (a Cellochoroid missing half of its normal body by weight would have only half of its normal Intelligence score, for example). Lost body parts can be replaced by finding and absorbing the same total mass of Cellochoroid moss, which also restores an appropriate amount of lost Intelligence. This modification to a Cellochoroid's Intelligence score only includes its base Intelligence score, including increases due to level, racial modifiers, and permanent or instantaneous inherent bonuses, but not other modifications such as enhancement bonuses, ability damage, and ability drain. A Cellochoroid whose base Intelligence score drops below 3 in this way dies, as it has insufficient psionic power to bind itself together.
Redundant Sentience (Ex): Due to their communal mind, Cellochoroids are somewhat vulnerable to mind-affecting affects. They do not have the racial immunity to mind-affecting effects that is normally granted by the Plant type, but instead add their Intelligence modifier (if positive) to all saves against mind-affecting effects. They can still gain immunity to mind-affecting effects normally (including from having a type other than Plant that normally grants it).
Skills: A Cellochoroid has a +2 racial bonus on all Disguise checks and a +4 racial bonus on Escape Artist checks. Their mutable form allows them to far more easily adjust their shape, although they lack fine control of their features.
