Baby wee man
Dress wee man up as a baby. Put him in a stroller and give him a recording of a baby crying. Walk the streets with him. Stop people on the streets and ask them to watch him while you go into the store really quick. After they agree to watch him run away. When they are standing there looking confused have wee man play the recording. Watch the person's reaction when they find out it is wee man. Also you can also leave wee man on the streets in the stroller and see what people would do after they find out it is wee man and not a real baby.