Relates several episodes in the friendship of two hippopotamuses.
- ISBN13 9780395199725
- Publish Date 11 September 1974 (first published 1 January 1972)
- Publish Status Active
- Out of Print 14 December 2009
- Publish Country US
- Publisher Houghton Mifflin
- Imprint Houghton Mifflin (Trade)
- Format Paperback
- Pages 48
- Language English