Based on an idea by "Slagger the Chuul" of the Wizards of the Coast online community.

A soft rustling sound emanates from a spot nearby as a patch of silvery grass surges forward like a carpet of worms.

Sheengrass is a form a psionic-sensitive grass. It appears to be normal grass: Its long, green blades have a faint silver tint. In swarms consisting of thousand of blades, sheengrass forms a hive mind and gains psi-like abilities. Sheengrass swarms attack instinctually and usually defend themselves from creatures that would trample or eat them.

Evil psions have been known to cultivate fields of sheengrass around a fortress or stronghold. Some believe that a hive mind can communicate telepathically, though they infrequently do so.

Sheengrass swarms understand Common, but cannot speak.

Combat

Once a sheengrass swarm attacks a target, it does not stop. Either the swarm must be destroyed or the target must flee.

Distraction (Ex): Any living creature vulnerable to the swarm's damage that begins its turn with a swarm in its square is nauseated for 1 round; a DC 12 Fortitude save negates the effect. Even with a successful save, spellcasting or concentrating on spells within the area of a swarm requires a Concentration check (DC 20 + spell level). Using skills requiring patience and concentration requires a Concentration check (DC 20). The save DC is Constitution-based.

Psi-Like Abilities: At will -- energy stun (+1d6 damage, DC 10*), psionicdaze (one humanoid creature that has 6 or fewer HD, DC 8*), psionicgrease. Manifester level 3rd. The save DCs are Charisma-based.

*Includes augmentation for sheengrass swarm's manifester level.

Tangle Grass (Ex): Asheengrass swarm clutches at the feet of any creature that begins its turn with the same space as the swarm or that moves into the swarm's space during its turn. An affected creature must make a DC 14 Reflex save or fall to the ground, prone. Falling prone ends the creature's turn. A prone creature in the swarm's space must make a Reflex save at the beginning of turn. If the save fails, the creature remains prone and its turn ends. The save DC is Dexterity-based.

Earth Root (Ex): A sheengrass swarm can travel only on soft natural ground (such as soil or earth, but not stone). It cannot be knocked down or blown away by wind effects.

Hive Mind (Ex): Any sheengrass swarm with at least 1 hit point per Hit Die (or 3 hit points, for a standard sheengrass swarm) forms a hive mind, giving it an Intelligence of 5. When a sheengrass swarm is reduced below this threshold, it becomes mindless and has no psi-like abilities.

Swarm Traits:A swarm has no clear front or back and no discernable anatomy, so it is not subject to critical hits or flanking. A swarm composed of Fine or Diminutive creatures is immune to all weapon damage.

Reducing a swarm to 0 hit points or fewer causes the swarm to break up, though damage taken until that point does not degrade its ability to attack or resist attack. Swarms are never staggered or reduced to a dying state by damage. Also, they cannot be tripped, grappled, or bull rushed, and they cannot grapple another.

A swarm is immune to any spell or effect that targets a specific number of creatures (including single-target spells such as disintegrate), with the exception of mind-affecting effects if the swarm has an Intelligence score and a hive mind. A swarm takes a -10 penalty on saving throws against spells or effects that affect an area, such as many evocation spells or grenadelike weapons. If the area attack does not allow a saving throw, the swarm takes double damage instead.

A swarm rendered unconscious by means of nonlethal damage becomes disorganized and dispersed, and does not form again until its hit points exceed its nonlethal damage.

Telepathy (Su): A sheengrass hive mind can communicate telepathically with any creature that speaks a language, provided they are within 15 feet. It can speak and understand Sylvan.

Tremorsense (Ex): A sheengrass swarm can detect anything moving in contact with the ground within 30 feet of itself.

Skills: A sheengrass swarm gains a +8 racial bonus on Hide checks among grass and similar ground coverings.

More Psionic Monster Mayhem