Catriona was a member of the Loughlin Family, a powerful family of druidic witches who came to the United States in the early 20th century. The Loughlin Family had many witches come to live with them to study their magic for a price. Amongst these was Rowena MacLeod after she was kicked out of her homeland by the British Men of Letters, but Catriona and her siblings treated Rowena cruelly. While powerful, all of the family but Catriona and her brothers Boyd and Gideon were killed by hunters. The three siblings managed to escape with the Black Grimoire, their spellbook, but were believed dead aside from a few rumors by all including other witches.
In 2017, while living in Eureka Springs, Arkansas, the siblings' accountant Barry Gilman ripped them off. While Gideon urged Catriona to let it go, she hexed Barry to have his stomach filled with money to kill him. This drew the attention of hunters Sam and Dean Winchester, the latter of whom killed Gideon, but not before Gideon cursed him to lose his memory. The next night, Catriona and Boyd discovered Gideon's body and were enraged, deciding to bring their brother back by switching his soul with Sam's. Tracking down the siblings, Sam attempts to force Catriona to give him what he needs to break the curse, but instead she and Boyd ambush Sam and knock him out.
As the siblings prepare the ritual, Catriona hears someone enter the house and is surprised to find Rowena. After learning who Rowena is, Catriona taunts her about their past and the two witches engage in battle. Catriona quickly pins Rowena to a wall with telekinesis and throws a glass shard at Rowena's head, barely missing her. Before Catriona can try again, Dean enters armed with a gun, amusing Catriona as bullets can't hurt her. However, Dean holds up a note with "witch-killing bullets" written on it before shooting Catriona in the head, killing her. After killing Catriona, Dean kills Boyd as well. Rowena then cured Dean of the memory curse by using a spell from the Black Grimoire.
Powers and Abilities
Catriona was a very powerful witch. She was a master of Druidic magic, with her power being enough to defeat Rowena MacLeod.
- Spell Casting - She was able to conjure her will into reality with a spell. She would have performed a Druidic Resurrection Spell if had she not been impeded.
- Hexing - Catriona also was able to hex Barry Gilman to have his stomach stuffed with money to kill him.
- Telekinesis - Catriona was able to easily pin extremely powerful witch Rowena MacLeod to the wall with her mind.
- Invulnerability - Catriona was invulnerable to most forms of harm as shown with her scoffing at the idea of a bullet being able to harm her.