so and so is taken by a fey mood!

[Lord Strong]

what the heck is a fey mood?

[Alexandyr]

It's one of the types of strange moods that can afflict a dwarf. This means they intend to create an artifact. Follow them and you'll see them claim a workshop, select the workshop and you'll get hints about what materials they need. As long as those materials are in a stockpile somewhere, they'll gather them automatically and get to work.

[Mr_Trip]

It's a strange mood type, which some dwarves will feel that leads them to create an artifact.
Some strange moods will give the dwarf a legendary crafting skill level at the end of it, if the need is satisfied. I do not think fey moods grant skill, but I may be mistaken. If they do not have the need satisfied they will go insane in some way.

[Sinclair]

Important note: there are three types of thread and three types of cloth in the game (plant, wool/yarn and silk). It might happen that the dwarf will want a specific one of these, but won't always tell you which one.

[Denesta]

Originally posted by Mr_Trip:

I do not think fey moods grant skill, but I may be mistaken.

The possessed mood is the only one that doesn't give xp. Since it is not actually the dwarf doing the crafting but what ever possessed it instead.

[Mr. Shaggnificent]

The other day a child got a fey mood and took over a craftshop. It was only the second or third year so there were very few resources, and one of the pieces he wanted wasn't available.

Long story short, it took three trips to carry all of him to the tomb.