In the not-so-pretty house where she lives with her dad and bunny Snowball, Annie plans to make some changes in the decor with the help of her next-door neighbor and cousin Henry and his big dog Mudge.
After noticing that a visiting hummingbird likes her pink petunias, Annie and her rabbit Snowball, accompanied by Henry and his dog Mudge, fill the garden with pink objects to attract more hummingbirds.
While enjoying autumn weather and activities, Mr. Putter, realizing how much he misses going to school, takes his cat Tabby, their adventurous neighbor, Mrs. Teaberry, and her cake-loving dog Zeke to "Show and Tell."
Henry and his dog Mudge are invited to a sleepover in Patrick's attic, where they watch monster movies, eat pizza, and enjoy a contest to determine whose dog is the best popcorn catcher.
Annie and her pet rabbit, Snowball, invite Henry and Mudge to a dress-up birthday party, but there is some confusion about what the guests are supposed to wear.
When Mr. Putter cannot sleep after eating too many of Mrs. Teaberry's pineapple jelly rolls, he and Tabby take a moonlit stroll that ends with the perfect neighborly gathering.
When Mr. Putter and Tabby take Mrs. Teaberry to the Conservatory for her birthday, Zeke tries his best to stay out of trouble, but one of the trees is irresistible.
At first Henry's very neat cousin doesn't like the cookies from under his bed or Mudge's slobbery kisses, but when they all play frisbee, she begins to enjoy her visit.