Undead Traits

Undead Traits and the Undead Type have the basic, following traits/aspects:

• Darkvision.
• Immunity to all mind-affecting effects.
• Immunity to poison, sleep, paralysis, stunning, disease, and death effects. (half of which is redundant with mind immunity, but whatever)
• Not subject to critical hits, ability drain, energy drain, ability damage, or fatigue.
• Healed by negative energy, damaged by positive energy. (only applies to Cure/Inflict spell lines, AFAIK, plus Heal/Harm)
• Proficient with whatever weapon and armor it has.
• Breathless.

This should apply to Undead Polymorph/Shapechage forms.