An undead creature possesses the following traits (unless otherwise noted in a creature’s entry).
Darkvision out to 60 feet.
No Constitution score, is immune to any effect that requires a Fortitude save and uses its Charisma modifier for Concentration checks.
Immunity to poison, sleep effects, paralysis, mind-affecting effects, stunning, disease, and death effects.
immunity to non-magic weapons. Magic, psionics and fire effect them normally.
Not subject to critical hits, nonlethal damage, ability drain, or energy drain, is immune to ability damage to its physical ability scores and is not at risk of death from massive damage, but when reduced to 0 hit points or less, it is immediately destroyed.
Cannot heal damage on its own, although negative energy can heal undead creatures. Resurrection spells turn undead creatures back into the living creatures they were before becoming undead.
Undead do not breathe, eat, or sleep and are immune to fatigue and exhaustion effects.
Undead have an aura of fear that cause any living creature to become panicked. They are subject to a will save DC 10+ the level of the undead creature. This aura has a 10ft radius.
Undead exposed to direct sunlight take 1 point of fire damage every round.