uncommon ne gargantuan electricity undead 

Perception +32; darkvision, true seeing

Languages Abyssal, Aklo, Celestial, Common

Skills Acrobatics +33, Arcana +37, Athletics +33, Nature +37, Occultism +37, Religion +40

Str +10 Dex +8 Con +6 Int +5 Wis +7 Cha +8

AC  43; Fort +29, Ref +32, Will +35

HP 390, fast healing 15, negative healing; Immunities cold, death effects, disease, electricity, negative, paralyzed, poison, precision, unconscious; Weaknesses good 15; Resistances cold 15, fire 15, physical 15 (except bludgeoning)

Light to Dark [R] (divine, negative) Trigger A creature uses an ability or spell with the positive trait within 120 feet of the tzitzimitl; Effect The tzitzimitl inverts the energy used in the triggering ability or spell, causing it to lose the positive trait and gain the negative trait, and changing all instances of positive energy or healing in the ability's description to negative energy.

Speed 50 feet, fly 60 feet

Melee [>] claw +34 (agile, magical, reach 20 feet), Damage 4d12+10 slashing plus 3d8 electricity and drain life

Ranged [>] eye beam +34 (range 100 feet), Damage 4d12 electricity plus 10d6 force

Occult Innate Spells DC 38; 9th darkness (×3), teleport, wail of the banshee; 7th eclipse burst, teleport (×3); 5th Abyssal plague; 4th darkness (×3); 3rd haste (×3); Cantrips (9th) detect magic; Constant (6th) true seeing

Drain Life When a tzitzimitl's claw Strike deals damages to a living creature, the tzitzimitl gains 20 temporary Hit Points, and the target must succeed at a DC 41 Fortitude save or become drained 2. Further damage dealt by a tzitzimitl's claw Strike increases the value of the drained condition by 2 on a failed save, to a maximum of drained 4.

Eclipse [>>] (cold, occult) The tzitzimitl casts darkness and drains the heat and warmth from the darkness spell's area, and each creature within the spell's area must attempt a DC 41 Fortitude save. Critical Success The creature takes 4d8 cold damage.Success The creature takes 8d8 cold damage and is slowed 1 for 1 round.Failure The creature takes 16d8 cold damage and is slowed 1 for 1 minute.Critical Failure The creature takes 16d8 cold damage, is slowed 2 for 1 minute, and is doomed 1.

Bestiary 3, page 279. Originally in AoA6.