4. The Cat Who Saw Red  1986
5. The Cat Who Played Brahms  1987
6. The Cat Who Played Post Office  1987
7. The Cat Who Knew Shakespeare  1988
8. The Cat Who Sniffed Glue  1988
9. The Cat Who Went Underground  1989
10. The Cat Who Talked to Ghosts  1990
11. The Cat Who Lived High  1990
12. The Cat Who Knew a Cardinal  1991
13. The Cat Who Moved a Mountain  1992
14. The Cat Who Wasn't There  1992
15. The Cat Who Went into the Closet 1993
16. The Cat Who Came to Breakfast  1994
17. The Cat Who Blew the Whistle  1995
18. The Cat Who Ate Cheese ?  1996
19. The Cat Who Tailed a Thief ?  1997
20. The Cat Who Sang for the Birds  1998
21. The Cat Who Saw Stars  1999
22. The Cat Who Robbed a Bank 200
23. The Cat Who Smelled a Rat 2001
24. The Cat Who Went Up a Creek  2002
25. The Cat Who Brought Down the House  2003
26. The Cat Who Talked Turkey  2004
27. The Cat Who Went Bananas  2004
28. The Cat Who Dropped a Bombshell  2006

also
The Cat Who Had 14 Tales  (short stories)
Short and Tall Tales  2002
The Private Life of the Cat Who ...: Tales of Koko and Yum Yum (from the Journals of James Mackintosh Qwilleran)