Undead Immunities
Undead are immune to the following effects, unless the effect specifies it works against undead creatures.
- Bleed, death effects, disease, mind-affecting effects, paralysis, poison, sleep, and stun.
- Ability damage, ability drain, energy drain, exhaustion, fatigue, negative levels, and nonlethal damage.
- Any effect that requires a Fortitude save (unless the effect works on objects or is harmless).
Format: Immunities undead immunities.
Source
Alien Archive pg. 158