Hidamari no Tami, or Nohonon, is a Japanese "relaxation toy" made by Tomy.
It's powered by solar cells, and when the sun (or a very bright lamp) shines on it it nods its head, back and forth in a very soothing manner.
Because there is no real motor but just a magnetic coil pulling it from side to side it runs completely silent.
My Hidamari
Box
Display from Japanese Toys'r'Us, pic from my friend KEL.
Insides, from some Japanese site
Bonus card sets from Tomy's site
Links
Tinkerville
