Join Mercer Mayer's classic and beloved character, Little Critter(R), as he plans the most fun sleepover ever Little Critter invites Tiger to have a sleepover in his tree house, and he wants everything to be just right. Little Critter can't wait to have the best time ever, from playing games to eating treats.But when things don't go according to his plan, Little Critter has to learn that change is okay when you've got a best friend. Little Critter: Just My Best Friend is a My First I Can Read book, which means it's perfect for shared reading with a child.