3D-printed Pikachu necklace with OLED display, Digispark and rechargeable battery. Custom your own animations with Arduino.
The I used what I had at home version of Adafruit's BMO. Using digispark board, LED matrix, buzzer with rechargeable battery.
Yet another pin using an ATtiny.
Yet another Nyan Cat board with ATtiny85. This time using rechargeable battery and WS2812. <3