FBI parte due
Folces Weard
I can post some clues if you all want me to.
It's triangular, and only similar to the Jew's Harp in terms of size. As far as I know, it's the only one of its kind, but it has a specific name and was designed by a person known for creative things like that.
In a search for new sounds, Moondog also invented several musical instruments, including a small triangular-shaped harp known as the "Oo", another which he named the "Ooo-ya-tsu", and (perhaps his most well-known) the "Trimba", a triangular percussion instrument that the composer invented in the late 40s.