(defun perl-dbg ()
  "Insert a debugging print statement"
  (interactive)
  (insert "use Data::Dumper qw( Dumper );\nwarn Dumper [ ];\n")
  (search-backward "[ "))

(global-set-key "\C-c\C-p" 'perl-dbg)
[download]

Then typing CTL-C CTL-p inserts this text:

use Data::Dumper qw( Dumper );
warn Dumper [ ];
[download]

and leaves the cursor under the [ character. I wasn't sure if you wanted to prompt for the name of the variable(s) to dump, so I changed (defun perl-dbg (name) to (defun perl-dbg (). The statement (interactive) makes it interactive, so that it can be bound to a key combination. Here's a version that prompts for a variable name (or names):

(defun perl-dbg (name)
  "Insert a debugging print statement"
  (interactive "svariable to dump: ")
  (insert "use Data::Dumper qw( Dumper );\nwarn Dumper ")
  (insert name)
  (insert ";\n"))
[download]

There are probably better ways to handle strings in Emacs-Lisp, but I've only recently started playing with it.