Willis doesn't look like an alien with a price on his head. He is round and furry and is always being mistaken for young Jim Marlowe's pet. Yet he is worth sixty thousand credits to any Earth zoo-keeper. Jim and his friend Frank know it's time for both them and Willis to go on the run.
- ISBN10 0345013883
- ISBN13 9780345013880
- Publish Date 1 January 1990 (first published December 1963)
- Publish Status Out of Print
- Out of Print 26 February 2014
- Publish Country US
- Imprint Del Rey Books
- Edition Revised ed.
- Format Paperback (US Mass Market)
- Language English