When this project was built for Halloween 2014, the Adafruit Audio FX Sound Boards with integrated amplifiers were not available, so the original added an Adafruit amplifier to an unamplified board (which is fine also).
The design uses a trigger to the audio board and reuses the toy's speaker for output.
The existing toy circuit board makes a good trigger switch for the new circuit. Fabricating a new trigger-activated switch is fine but reusing the existing board is less expensive and works well. Remove the board along with the red and black wires. The black wire may be removed from the board (cut it about 3 inches long).
Scrape a bit of the blue solder mask off carefully, exposing a copper trace, near the silver membrane trigger switch. Solder a wire to the exposed trace. It helps to tin the trace and wire with solder before connecting them together. The red wire should remain connected where it is.
Build the circuit shown below below using the Adafruit Sound FX Board with Amplifier. The trigger shown is the one modified above.
On the bottom of the amplifier board, solder on a JST connector for power (more later).
The speaker in the toy was reused for the new build. If you want a better sound, you can source a better speaker, but be careful of size and mounting options.
Circuit with the Adafruit Sound FX board with integrated amplifier.
If you have the Adafruit Sound FX board without amplifier (like I had), you can add an additional amplifier board. I used the Adafruit TS2012 amplifier set to maximum amplification.
Just like the circuit above, the Sound FX board below has a JST connector soldered to the bottom of the board to provide circuit power.
Circuit with an Adafruit Sound FX Board and external amplifier.