Fey'ri are not a true elven subrace. They are to elves as tieflings are to humans and tanarukks are to orcs. The fey'ri are the result of interbreeding between sun elves and tanar'ri in an attempt to strengthen the sun elf bloodline. More information can be found here.
Fey'ri have an ECL +1 in CoA.
Dexterity +2, Intelligence +2, Constitution -2.
Darkvision. Skill affinity (+2): Bluff, Hide, Search.
Damage reduction 10/+1, Fire resistance 10/-
Saves vs. poison and electrical +2.
Normal elven bonuses still apply.
Alter Self: Fey'ri can use Alter Self to assume humanoid shape and maintain this indefinitely. (Due to a bug in the scripting, alter self changes your appearance permanently and cannot be returned to original. It also alters everyone into the same appearance.)
Favored class: Sorcerer (?)