Quantity   Component name
1 × Espruino Pico µC
2 × Adafruit Electret Microphone Amplifier - MAX4466 with Adjustable Gain an electret breakout from the Adafruit friends
1 × Piezo among the cheapest & tiniest speaker
1 × MicroSD -> SD adapter
1 × Adafruit Pro Trinket LiIon/LiPoly Backpack Add-On also from Adafruit, the tiniest battery charger I could find
1 × LiPo 3.7V 1200mA quite a big battery for such a tiny pluche !
1 × Sock(s) not too old if you wish to make it a gift to someone :)