the 3 Blairs leave to take a walk in the park. A bear named Somebody, walks into the house, eats their breakfast, sits on the chairs, makes a mess in the kitchen, tries to find something to drink, and somewhere to sleep. The Blairs come back home and saw the mess, and found the bear in the baby boy's cradle. But Somebody leaves down the drainpipe and the boy waves bye.
http://cmars.cwmars.org/search~S34/