Alien (CR +1)

Alien creatures dwell in the furthest planes, but can be summoned using spells such as summon monster and planar ally. An alien creature's CR increases by +1 only if the base creature has 5 or more HD. An alien creature's quick and rebuild rules are the same.

Rebuild Rules

Senses The creature gains darkvision 60 ft.
Defensive Abilities The creature gains damage reduction and energy resistance as noted on Table: Alien Creature Defense.
SR The creature gains spell resistance equal to its new CR +5
Special Attacks The creature randomly gains (roll 1d6) one of the advantages from the Alien Advantages list.

Table: Alien Creature Defenses
Hit Dice Resist Acid, Cold and Fire DR
1-4 5
5-10 10 5/magic
11+ 15 10/magic

Table: Alien Creature Advantages 
Roll Effect
1The creature gains the crazed gaze attack that deals 1 point of Wisdom damage to a single target as a swift action, once per round. A successful Will save (DC 10 + 1/2 the creature’s Hit Dice + the creature’s Wisdom modifier) negates the damage.
2The creature gains an acid aura that deals 1 point of acid damage each round to any adjacent creature. It also increases it’s the acid resistance of the creature by 5.
3The creature deals 1d4 points of cold damage with its primary natural attacks.
4The creature grows two tentacles and gains a slam attack that deals damage according to its size.
5The creature can cast enlarge person on itself three times per day.
6The creature’s DR type changes from magic to untyped. For example, a creature with DR 5/magic becomes DR 5/ —.