Birth & up. What began as a simple errand to the laundromat becomes a desperate journey as the entire family joins together to rescue Trixie's Knuffle Bunny. This charming Knuffle Bunny set features your very own Knuffle Bunny plush and Mo Willems classic book, "Knuffle Bunny: A Cautionary Tale." Hang tightly onto your Knuffle Bunny as you read. You don't want to lose him. Hardcover. 40 Pages. Plush size: 12.25"H.