Jim Panzee wakes up in a bad mood one beautiful day, but he keeps denying he is grumpy even as his friends give advice for feeling better.

"A chimp's big sneeze wreaks hilarious havoc in this delightful companion book to The Hiccupotamus."--

When Violet has a numbers problem and Arthur is penniless, they go into business and solve both problems.

Willy is unhappy that he is being followed by a cloud that will not go away.

While hurrying to get on the school bus, Arthur and his friend unknowingly switch their lunchboxes; later Arthur finds out what surprise his sister had put into hers.

"On the spookiest night of the year, Jim Panzee and his jungle friends brave the dark to collect treats. Not only does the jungle look different at night, it sounds different. What's that knock-knock-knock and that HAHA HAHA HAHA? And the smell? PEE-YEW! "Don't be scared," they tell Jim. But then two glowing eyes flash overhead, and looking for treats is almost abandoned"--

Arthur the chimpanzee is determined to be the best all-around gymnast at his gymnastics birthday party.

"Hilarious chaos ensues when Jim agrees to watch Oxpecker's egg, which rolls away while he takes a break for lunch and ends up in Snake's nest where the snake hatchlings think Jim is their mother"--

"Jim Panzee is faced with something everyone hates...waiting...and waiting...and more waiting. Jim tries to be patient but he's even impatient waiting for patience. It doesn't happen right away, but eventually, Jim realizes that some things are worth waiting for"--

A celebration of the universal feeling of grumpiness invites the youngest Grumpy Monkey fans to join Jim Panzee as a growing number of objects, from a banana and a ball to crayons and a kite, fail to cure his grumpiness.