The Skelecaster 

It's a little gross.

A man who goes by the name “Prince Midnight” has built a functioning guitar out of a skeleton, and I can’t think of anything more metal than that.

“[N]ow Uncle Filip can shred for all eternity. That’s how he would want it. I’m super proud of the project and how it serves to honour him, his life and his influence on me.”

Rock on, Uncle Filip.

Update (February 22, 2021): It appears there are some questions about this story, as reported by Vice, among others. Is the backstory of a dead uncle the fictitious work of a prankster? It seems distinctly possible. However, the Skelecaster certainly does seem to exist, and it may well be built with a real human skeleton:

As for the Skelecaster and whether or not it’s actually made from a human skeleton, an orthopedic surgeon reviewed the photos of Filip’s bones at my request, and could only say that there wasn’t any evidence to suggest that the skeleton didn’t belong to a human male.

If it’s a real skeleton coupled with a fake backstory, that just makes the whole story even weirder. If it turns out to be a fake skeleton, well, that will be a shame.