Author:  Boynton, Sandra, Boynton, Sandra 
Baby books
Published on 6 November 2000 by SIMON & SCHUSTER (Simon & Schuster Children's) in the United States.

Board Book | 12 pages, full colour
156 x 129 x 21 | 272g
One hippo, all alone, calls two hippos on the phone. So begins this counting story, in which exuberant hippopotamus guests show up in ever-increasing numbers, until an all night party is inevitable.