I started by skimming the Camel and tried using it as a reference book. It didn't work as a reference book, at least for me. Later I read the Llama, after the Camel it didn't teach me much and it was just as bad as a reference. (Programming I knew, Perl I didn't.)
The Perl Pocket Reference on the other hand I use all the time. Appart from minor omissions (like the range / flip-flop operator), it is an excellent pocket reference. So, the book I'd like to see would be "The Perl Reference": an expanded Pocket Reference that doesn't attempt to teach programming Perl, but that provides Programming Perl level of reference material in a Pocket Reference format. That is, take the Pocket Reference entries and expand them to deal with the edge cases and idiom that the Pocket Reference hasn't room for.
DWIM is Perl's answer to Gödel