You are cordially invited to the birthday event of the year! Babymouse is having a birthday and she wants it to be BIG! Mount Everest BIG. Eiffel Tower BIG. Tyrannosaurus rex BIG. (Okay, maybe inviting a T. rex isn't such a good idea). Will all of Babymouse's birthday dreams come true? Will she have a five-hundred-tier cupcake? Find out in Happy Birthday, Babymouse—the eighteenth hilarious, action-packed installment of the beloved Babymouse graphic novel series by Matthew Holm and Jennifer L. Holm!