In Celtic Mythology the Korrigan are one of three things. The first is a generic term for Fae, interchangeable with Sidhe/Seelie/Sith. This, however, may be more of a misunderstanding with 16-18th century writers in regards to terminology. Korrigan are also considered, in some folklore, to be small dwarf-like creatures banished to the mortal world. Finally, the Korrigan are, in some other folklore, described as beautiful young women who reside near Dolmans and streams and delight in tricking people to their deaths and kidnapping children.
For Creatures of Eira, I have cherry picked, pieces of the later two sources.
Korrigan’s are fae of great unnatural beauty who serve as guardians of Dolmans, rivers, streams and creeks. According to Au-Sidhe legend, the Korrigans were once Au-Sidhe who refused to fight in the war against the Un-Sidhe. Angered by their lack of loyalty, the Day Queen, leader of the Au-Sidhe, and a priestess of Eir, banished them from the Eternal Lands and forbad them from crossing the Eastern or
. Endless Seas
Trapped on Eira, the Banished Au-Sidhe sought refuge from mortality by bargaining with the Night Queen of the Un-Sidhe. However, the Night Queen was a cruel mistress and while granting the wish to retain their immortality, forbad the banished ones from the Dark Lands.
Since then the Korrigan have vowed to watch the Dolmans of Eira, the ancient gateways to the Fae roads to strike vengeance on any who try to move through the Dolmans. Over time, they expanded their watch, to the water to wait for any who may attempt the far older and far more dangerous roads.
Hit Dice: 4+4
Armor Class: 13
Attacks: Weapon (1d6)
Saving Throw: 13
Special: Fae Step, Hypnotic Song, Regenerate
Challenge Level/XP: 4/120
Fae Step – Can travel up to move limit instantly, but never through solid matter.
Hypnotic Song – Works as Charm Person spell, save negates. Note: Once a person has been under the influence of a hypnotic Song once all further attempts are easier. Target takes a negative modifier to his saving roll equal to the amount of times he has been under the influence of Hypnotic Song.
Regenerate – Korrigans replenish 1 HP per round after they are brought below half their normal hit points.
As immortal Fae originally from the Eternal Lands, the Korrigan find iron and all things made of it (including alloys) to be toxic. When injured by iron the Korrigan receives an extra point of damage in addition to the damage they receive normally from that weapon.
Note: due to their bargaining with the Night Queen, Korrigan are less susceptible to iron than normal Sidhe.