rare ln small construct 

Perception +25; darkvision, true seeing

Languages — ; truescript

Skills Arcana +27, Deception +24, Stealth +25

Str +1 Dex +6 Con +1 Int +8 Wis +8 Cha +5

Truescript A living rune can't speak, but it can sculpt its form into complicated scripts and pictographs that can be understood by any creature with the ability to read written language. A living rune can also understand any written or spoken language.

AC  34; Fort +20, Ref +23, Will +27

HP 245; Immunities poison, death effects, diseased, doomed, drained, fatigued, healing, necromancy, nonlethal, paralyzed, sickened, unconsciousness

Backdrop When a creature attempts to Strike a living rune and critically misses, the attacker hits the surface (a canvas, wall, or so on) behind the living rune. This might damage the surface or the attacker's weapon, at the GM's discretion.

Surface-Bound A living rune can move only along flat surfaces. If the surface it's on is destroyed (such as a portrait hit by a fireball spell or a wall being smashed), the rune takes 7d6 damage and is shunted to the nearest flat surface. If there is no flat surface within 5 feet, the rune is destroyed.

Speed 25 feet

Ranged [>] electrical blast +25 (electricity, evocation, range increment 60 feet), Damage 4d12 electricity

Arcane Innate Spells DC 35, attack +27; 7th prismatic spray (×2); 6th chain lightning, disintegrate, glyph of warding (at will), wall of force; 5th black tentacles (×2), cloudkill (×2); Cantrips (7th) detect magic; Constant (6th) true seeing

Bestiary 3, page 163.