Baloo is a bear from the story The Jungle Book who sings The Bear Necessities. To live, most people need at least the bare necessities to survive. Thus, the joke is that Baloo the bear needs the bare, or "bear," necessities.
In the original story The Jungle Book the illustrations of characters like Baloo the bear were done by John Lockwood Kipling, who was the father of Ruyard Kipling. There have been other artists that have illustrated Baloo, but Lockwood is the original artist.