I am sad to admit that I no longer have the files to screenshot this, but one of my more recent forts produced what may be the strangest artifacts I have ever seen.
My first two possessions were dismal failures (let nobody say I am good at the game), but the third was a weaver who was able to claim a clothier's shop and start working. After a while, he produced... a legendary pair of pants, with a picture of him holding them on them.
This would normally not be particularly interesting beyond the sheer silliness of recursive artifact pants, but my fortress quickly developed an obsession with the damn things. When my engraver was not engraving goblins dying horribly at the hands of bugged dogs, what was he engraving? Himself slaying the Magma Man and granting my fort access to the magma tube? No. He was engraving the pants.
After a good sixty engravings of the pants, I got another mood. This one resulted in a wooden statue. With a picture of the pants on it.
The statue, naturally, later proved to be of great use in decorating the count's bedroom, but there was still a prolific number of engravings of the pants. Eventually I got a few more fey moods and some actually valuable artifacts started popping up, sans engravings of pants.
Then, eventually, I got a fey mood on an armorer. I made ready his magma forge and all possible resources, eager to enjoy my new legendary armorer and whatever artifact armor he chose to make. What DID he choose to make?
Artifact iron pants.