The turtle's shell is a stack of batteries.
The turtle wears a hat that looks remarkably similar to a piezo buzzer. When his legs rest on a metal surface, the turtle begins to sing.
There is also what looks like a headphone jack. With a cable connected, the turtle has a tail. The tail grants the turtle a better bass performance. An interlock automatically switches the audio route.
The regular reader may have guessed what drives the guts of the turtle. This time a substantial upgrade to the sound quality is afforded by utilizing ELM ChaN's Wavetable Synthesis in conjunction with my MIDI converter script for it.
Perhaps, in time, an entire zoo of chiptune chirping critters can be unleashed.