Jacoby is an NPC Sidhe run by Morgan.
Background
Jacoby (emphasis is on the second syllable) is Lady Catherine's advisor on all things Fae. He was there to guide her through her reawakening and ensure she ended up in her rightful seat of Waldren House.
He is, technically, Squire Jacoby of the Seelie Court, a member of House Fiona like Catherine, but he is only ever referred to as Jacoby. If he has another name, no-one uses it.
It came out that Jacoby was formerly Count Tristran of House Gwydion and Lady Catherine's liege lord, before the Shattering. This old identity, once he found out about it, was the cause of some conflicts, and may in part be responsible for the death of Madame Rain.
A great deal of mystery surrounds Jacoby, though he has largely managed to keep it quiet. Now, of course, he is no longer at Waldren House, having undertaken a quest to find Madame Cérese.
Physical Description
In both Fae and mortal seemings he is a handsome man of around about thirty years of age, with auburn hair cut short and a tidy beard on his chin (and only his chin). He has been known to wear glasses but not with any regularity.
Demeanor
Jacoby acts slightly older than his thirty years, sometimes being a grumpy rules-stickler and other times a fussy worrier, but his affected stuffiness isn't such a good act and his good nature usually shines through. It is widely known that Jacoby is a good shoulder to lean on, and that his confidence is absolute.