Creatures with the entropic template live in planes where chaos is paramount. They can be summoned using spells such as summon monster and planar ally. An entropic creature’s CR increases by +1 only if the base creature has 5 or more HD.
An entropic creature’s quick and rebuild rules are the same:
Rebuild Rules: Senses gains darkvision 60 ft.; Defensive Abilities gains DR and energy resistance as noted on the table; SR gains spell resistance equal to new CR +5; Special Attacks smite law 1/day as a swift action (adds Cha bonus to attack rolls and damage bonus equal to HD against lawful foes; smite persists until the target is dead or the entropic creature rests).
Entropic Creature Defenses