Water and the Brain & Arthur the Unfunny

Water and the Brain: Muffy is throwing a party at a water park and everyone is excited except Brain. Arthur and Binky discover that the Brain is afraid of water and try to help him get over this fear so he can go to Muffy's party.
Arthur the Unfunny: In a letter to Buster, Arthur tells him about how he was determined to be too hopelessly unfunny to be a clown and how he discovered he can be funny using his piano.