Good Night Grizzly is a children's book created to educate young children about grizzly bears and their annual act of hibernation. The book made its first and only appearance in the episode "Hibernation".
Like many young children's books, Good Night Grizzly is a board book. Most of the pages have pull tabs that allow the images in the book to move, both to visually aid the readers in learning the information and for the readers' entertainment. The cover is a dark, almost grey color that is made to represent the night sky, as there are white dots to resemble stars. The image is of a grizzly bear sleeping with a pillow and blanket within a comically small and cartoon-like cave under the moon, with snow surrounding the cave. There is also a yellow stamp in the top left corner to signify the book as a best seller.
The Bears take a small visit a small bookstore. Grizzly is seen looking at various foods available while his brothers are looking at various books that fancy their interests. Panda ends up finding a book about pandas. Interested, he calls his brothers over and Ice Bear ends up finding a book about polar bears from the same section, the two reciting now facts from the books. Feeling left out, Grizzly quickly looks for a book about grizzly bears where he finds a children's book describing grizzly bears going through hibernation. He attempts to gain his brothers' approval by reading a common fact about grizzlies from the book, but the others don't really care. Feeling left out, he reads on and states he wants to hibernate, but Panda disapproves of the idea, stating it was January. Grizzly didn't listen and was set on hibernation.
Reading the book for instructions, Grizzly begins to prepare for the hibernation, from gathering and eating enormous amounts of food to stealing every soft object in the house for his "cave". He attempts to practice hibernating in the living room, but his brothers, now annoyed, begin to protest and attempt to persuade Grizzly to stop, but out of frustration, Grizzly instead hauls as much as he can to a shack outside of the cave. After making pre-hibernation preparations, he sets an alarm for June, then attempts to sleep. However, he finds himself unable to sleep, constantly tossing and turning.
After a while, Grizzly decides to give up on trying to fall asleep, ready to head back to the cave, when he hears a voice telling him to stay. He turns, confused, and looks inside of the book for a moment. Thinking it was nothing, he closes it and turns to leave once more, but he hears the voice again. Starting to get freaked out, he checks the book again and finds the grizzly bear inside has become animate. The bear then pulls Grizzly into the book and leads him through it, explaining how important hibernation is and insists on Grizzly following through with it. He allows Grizzly to eat several different foods and tells him nothing is stopping him from doing so. Growing excited, Grizzly decides to hibernate. However, after learning that there was nothing saying there would be an immediate resolution to his conflict with his brothers, Grizzly grows frantic at the fear that his brothers wouldn't be there for him again after he'd wake up and forget about him. He attempts to leave by runs back through the book while the grizzly bear begins to lecture him, telling him that his brothers would just laugh at him if he went back. However, Grizzly was persistent, and finally decided that he didn't want to be special as he'd been insisting before. With this revelation, the book closes around him.
- The book's art style resembles that of the Maisy series' made by Lucy Cousins.
- The name, however, is a reference to Goodnight Moon.