A zombie is permanently <a href="/condition/slowed">Slowed 1</a> and can&#x27;t use reactions.

Slow

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 untyped damage (DC 14 Basic Fortitude save) as its wounds fester.

Rotting Aura

Void Healing

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&#x27;s flesh to heal itself. This restores 1d6 Hit Points.

Feast

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

Gallop

Zombie Riding Horse - evil, mindless, zombie

A zombie is permanently @UUID[Compendium.pf2e.conditionitems.Item.Slowed]{Slowed 1} and can't use reactions.

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 @Damage[1d6[untyped]] damage (@Check[fortitude|dc:14|basic] save) as its wounds fester.

@Localize[PF2E.NPC.Abilities.Glossary.NegativeHealing]

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 @Damage[1d6[healing]] Hit Points.