uncommon n large arcane evocation mindless 

Perception +15

Skills Acrobatics +19

Str +4 Dex +4 Con +6 Int -5 Wis +0 Cha -5

AC  25; Fort +19, Ref +17, Will +15

HP 155; Immunities bleed, mental, negative, poison, death effects, disease, doomed, drained, evocation, fatigued, healing, necromancy, nonlethal attacks, paralyzed, sickened, unconscious

Absorb Evocation A roiling incant is made of evocation energy. Any time it would be affected by another creature's non-cantrip evocation spell, after applying its immunity, it also regains 5 Hit Points.

Speed fly 40 feet

Melee [>] arcane tendril +19 (arcane, evocation, magical, reach 10 feet), Damage 2d12+10 force

Ranged [>] arcane bolt +19 (arcane, evocation, magic, range increment 30 feet), Damage 2d10+10 force

Arcane Innate Spells DC 30, attack +20; 4th wall of fire (at will, see Unstable Magic); 3rd fireball

Engulf [>>] DC 28, 2d8 force plus 4d4 fire, Escape DC 28, Rupture 20 (page 305)

Unstable Magic A roiling incant is as much a mass of unstable magic as it is a creature. Is isn't living or undead, nor is it even a construct. It can't be healed or Repaired and is destroyed at 0 Hit Points, though it naturally recovers a number of Hit Points equal to its level × its Constitution modifier (54 for most roiling incants) each day. Each time a roiling incant casts one of its non-cantrip spells, it drains its own magic to do so, taking 5 force damage.

Bestiary 3, page 215.