You're not alone. I'm completely weirded out by this too.
This guy tells website MetalSucks he used his Uncle Flip's bones to make a guitar.
Flip's bones are over two decades old and had been used at a local college in Greece before giving him back.
The guy tells the site "the guitar plays perfect and sounds awesome" and that his Uncle Flip "can shred for all eternity. That's how he would want it."