Not sure if it is or isn't a Jew's Harp but according to Wikipedia, if it is, it's got a LOT of names:
"The Jew's harp, also known as the jaw harp, mouth harp, juice harp, gewgaw, guimbard, khomus, jew's trump, trump, Ozark harp, Galician harp, or murchunga is a lamellophone instrument, consisting of a flexible metal or bamboo tongue or reed attached to a frame."
Etymology (Also Wiki):
"There are many theories for the origin of the name Jew's harp. According to the Oxford English Dictionary, this name appears earliest in Walter Raleigh's Discouerie Guiana in 1596, spelled "Iewes Harp". The "jaw" variant is attested at least as early as 1774 and 1809, the "juice" variant appeared only in the late 19th and 20th centuries.
It has also been suggested that the name derives from the French "Jeu-trompe" meaning "toy-trumpet". (Though in the French idiom, if two substantives are joined together, the qualifying noun is invariably the last.)
Both theories—that the name is a corruption of "jaws" or "jeu"—are described by the OED as "baseless and inept". The OED says that, "More or less satisfactory reasons may be conjectured: e.g. that the instrument was actually made, sold, or imported to England by Jews, or purported to be so; or that it was attributed to them, as a good commercial name, suggesting the trumps and harps mentioned in the Bible.""