Two children’s book icons unite in this zany, mischief-filled picture book that’s both spooky and laugh-out-loud funny! Mary McScary loves being scary. Only her cousin, Harry McScary, seems immune to her usual tricks. Little does Harry know, he’s in for the scare of his life. R.L. Stine’s Goosebumps series has sold more than 350 million books in 32 languages, and Marc Brown’s Arthur books, apps, ebooks, and TV shows are available in more than 80 countries.