From Pathfinder Book of the Dead, which isn't enabled.

Zombie Snake

CREATURE 0

MEDIUM EVIL MINDLESS UNDEAD UNHOLY ZOMBIE

At around 5 feet long, this massive, rotting serpent lacks potent venom, but its bite still injects putrid fluid that can cause infection.

Simple to create and varied in purpose, these shambling undead are often used for their strength and endless stamina to conduct boring, repetitive tasks.

Perception +2; darkvision

Skills Athletics +5, Stealth +5

Str +3, Dex +1, Con +2, Int -5, Wis +0, Cha -2

AC 13; Fort +6, Ref +3, Will +2

HP 35, void healing; Immunities bleed, death effects, disease, paralyzed, poison, unconscious; Weaknesses vitality 5, slashing 5

Slow

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

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 20 feet, climb 20 feet

Melee Fangs +7, Damage 1d6+3 piercing plus Filth Fever

Filth Fever (disease)

The sickened and unconscious conditions from filth fever can't end or be reduced until the disease is cured

Saving Throw DC 14 Fortitude

Stage 1 carrier with no ill effect (1d4 hours)

Stage 2 Sickened 1 (1 day)

Stage 3 sickened 1 and Slowed 1 (1 day)

Stage 4 Unconscious (1 day)

Stage 5 dead

Pathfinder Book of the DeadOGL