Very great surprise ! Good idea to have a batterie spot.
BTW I guess several people would be interested in having only a hexapod. So maybe an idea would be to create only the Poppy Hexapod as a creature itself (without the upper body of a Poppy Humanoid) and then create a mix between a Poppy Torso and and Poppy hexapod.
In this way, it creates 2 creatures at the same time 
If you want to embed a computer, you can use the new Raspberry Pi 2 which is powerful enough for running pypot.