If video isn't your thing, here is a brief overview in text and pictures:
B.O. Bob in action:
B.O. Bob Raising one arm:
B.O. Bob scratching head:
B.O. Bob raising both arms (yawning):
B.O. Bob State Machine Logic:
A couple of the collision borders for the stink cloud:
Dave purchasing an Emergency Beard:
Dave putting on an Emergency Beard:
GIF of Dave applying beard in level
Logic for the Beard power-up
Let me know any thoughts or comments!
Links: