Bob Herzberg, BMO builder and blogger at BYOBMO.com , fills us in on the whys and hows and even the Pen Wards of creating interactive Adventure Time BMO props with the Raspberry Pi. A Conversation With BMO A conversation with BMO showing off some voice recognition capabilities. There is no interaction for BMO’s responses other than voice commands.

The rest is here:
I am Beemo, a little living boy: Adventure Time prop build