From Pathfinder Society Scenario #1-03: Escaping the Grave, which isn't enabled.

Zombie Riding Horse

CREATURE 1

UNCOMMON LARGE EVIL MINDLESS ZOMBIE

Perception +3; darkvision

Skills Athletics +7

Str +4, Dex -2, Con +3, Int +0, Wis +0, Cha +0

Slow

A zombie is permanently Slowed 1 and can't use reactions.

AC 13; Fort +6, Ref +3, Will +4

HP 50, void healing; Immunities death effects, disease, paralyzed, poison, unconscious; Weaknesses vitality 10, slashing 10

Rotting Aura (aura, disease)

10 feet. The zombie riding horse emits an aura of rot and disease that causes wounds to fester and turn sour.

Any living creature that starts its turn within 10 feet of the zombie and is not at full Hit Points takes 1d6 damage (DC 14 basic Fortitude save) as its wounds fester.

Void Healing

A creature with void healing draws health from void energy rather than vitality energy. It is damaged by vitality damage and is not healed by vitality healing effects. It does not take void damage, and it is healed by void effects that heal undead.

Speed 40 feet

Melee Jaws +7 (unarmed), Damage 1d8+4 slashing

Melee Hoof +7 (agile), Damage 1d4+4 bludgeoning

Feast

The zombie riding horse Strikes with its jaws against an adjacent living creature or a creature that has died in the past hour. On a success, the zombie riding horse can feast upon the creature's flesh to heal itself. This restores 1d6 healing Hit Points.

Gallop

The zombie riding horse Strides twice. It has a +10-foot circumstance bonus to its Speed during these Strides

Pathfinder Society Scenario #1-03: Escaping the GraveOGL