Daisy Moses/Granny (Irene Ryan), thinking the hippopotamus is a hog, wants to send it to a friend in Lee's Summit, Missouri. This is an actual town, a suburb of Kansas City, which had a population around 12,000 when this episode aired in 1967. By the year 2020, Lee's Summit, Missouri had grown to around 100,000 people.
A rare episode with no guest actors (unless you count the hippo).