Ralph-from the Robot Goose Collection

I sat and read a book one night When Ralph walked in and sat in a chair. A few minutes later Ralph came in, But he was already there. Again in a moment, Ralph walked in, So now there were three. I looked at him and him and him And said, "Do you have something to tell me?"
"It had better wait til Ralph gets here," As there was a knock at the door. Ralph answered it and it was Ralph, And now he numbered four. "It's very simple," Ralph explained In perfect unison, "There was a sale at Great Clone Mart, A good deal, four from one."