This creature is an enormous mass of pink-grey flesh on eight elephantine legs. Its head must be where two scythe-like tusks grow on sides of the orifice from which three long tongues extend. At the opposite end, it has three long, thin tails. Numerous compound eyes are spaced around the sides of the creature's body.
CR 15; XP 51,200
N Colossal Aberration
Init +2; Senses darkvision 60 ft., low-light vision; Perception +29
AC 30, touch 0, flat-footed 30 (–2 Dex, +30 natural, –8 size)
hp 250 (20d8+160)
Fort +15, Ref +6, Will +20
Defensive Abilities all-around vision, lumbering, psychic duality; DR 10/—
Speed 20 ft.
Melee tusks +23 (6d6+16, 15–20/×3 plus 2d6 bleed)
Space 30 ft.; Reach 20 ft.
Special Attacks trample (10d6+24, DC 27), tusk-scythes
Spell-Like Abilities (CL 30th; concentration +32)
At Will—create greater mindscape (DC 23), mindlink (DC 18, one or more targets within the mindscape shared with the grass-eater only), mindscape door (DC 20)
3/day—quickened create greater mindscape (DC 23), quickened mindscape door (DC 20)
Str 42, Dex 6, Con 24, Int 19, Wis 23, Cha 15
Base Atk +15; CMB +39; CMD 47 (59 vs. trip)
Feats Bleeding Critical, Critical Focus, Great Fortitude, Improved Critical (tusks), Improved Initiative, Iron Will, Lightning Reflexes, Quicken Spell-Like Ability (create greater mindscape), Quicken Spell-Like Ability (mindscape door), Toughness
Skills Knowledge (arcana) +24, Knowledge (dungeoneering) +24, Knowledge (nature) +27, Knowledge (planes) +24, Knowledge (religion) +24, Perception +29, Sense Motive +29, Survival +29
Language Aklo, Sylvan (doesn't speak); mindscape telepathy
Environment temperate plains
Organization solitary, pair, or troop (3—8)
Grassland Glyphs (Sp) Trails left by wandering grass-eaters can form potent magical sigils. Grass-eaters can use them to cast occult rituals, often with a casting time of days or weeks to produce effects of mythical magnitude. Known uses of grassland glyphs involve opening and closing of planar portals, sealing planar breaches, banishing extraplanar creatures, warding against supernatural entities and binding them. Other unrecorded effects are certainly possible, however.
Intuitive Spell-Like Abilities A grass-eater uses its Wisdom modifier to calculate saving throw DC of its spell-like abilities and make concentration checks.
Lumbering (Ex) A grass-eater moves through difficult terrain and obstacles two or more size categories smaller with ease. It cannot be grappled by creatures smaller than itself, and it cannot be entangled.
Mindscape Telepathy (Su) A grass-eater can communicate with sapient beings by drawing them into a benign mindscape and then using their mindlink spell-like ability. Once a grass-eater communed with a creature in this way, it can use its create greater mindscape ability on the same target at any range, even across the planes, though it changes its saving throw entry to "willing targets only". It can't reach creatures on planes and extradimensional spaces that are protected from divination, teleportation, or other forms of contact.
Psychic Duality (Su) A grass-eater drawn into a mindscape can perceive both the real world and the mindscape, and retains ability to act in both at the same time. Each time a grass-eater enters a psychic duel, it gains 100 temporary hits points that last until the end of the duel. A grass-eater has a typical pool of 38 manifestation points that it can use without negative effects.
Tusk-Scythes (Ex) A grass-eater's tusks are razor-sharp, having a base critical threat range of 18–20 and critical damage multiplier of ×3.
Grass-eaters are denizens of the Vast Green, a demiplanar plain (or possibly a cluster of similar/connected demiplanes) of infinite grasslands. They are strange and alien but mostly peaceful creatures that spend their long lives travelling the plains and tracing miles-long mystical glyphs in the grasses. They never fight each other but they rarely gather in larger groups either, probably capable of communicating with any members of their species with ease.
The scant contact with the creatures seem to imply their primary goal is maintaining integrity of their demiplane, protecting it from vaguely defined "invaders". They might be in conflict with, or being responsible for keeping imprisoned an enigmatic entity known as Green Scyther that can be encountered on the plains of the Vast Green.