Hello, monster!

"You probably know the feeling. You're playing happily by yourself in the park, when you're suddenly told, Go and say hello to that little boy over there!' But what if you don't want to say hello? What if the little boy isn't really a little boy at all? What if he's a monster in disguise? Welcome to a . . . 'what if?' story where saying hello can lead to all sorts of surprising adventures"--OCLC.