Today watching this Miku Chan video (control Vocaloid 2 trough the Miku Theremin seems great!) I discovered Keromin:  an eclectic electronic musical instrument in the shape of a frog puppet. Kero in its name is an onomatopoeia for song of a frog in Japanese (like in the anime Keroro Gunsho). Min is after "Theremin" by which Ithe japanese creator pays homage to the world's first electronic instrument created by Russian inventor Léon Theremin in 1919.
In playing the Keromin, the pitch is controlled with the angle between the thumb and other fingers which manipulate the puppet's mouth. The sounds programmed are those of instruments for orchestra and real frog songs as well as sampled human voice saying "kero-kero."


Like a Theremin, the pitch changes according to continuous movements--the opening of the puppet's mouth. It is, however, easier to play than a Theremin because the movements are converted into sounds in accordance with musical scales automatically.

And if the Miku Theremin and Keromin are not enough there is always Matryomin: the Matrioska Theremin invented by Masami Takeuchi in 1999 (via Gizmodo/Trend in Japan) and produced by Mandarin Electron (video here)....