Since it's Halloween, I decided to decorate my terminal as a "haunted house". It looks pretty scary, but the cpan prompt wasn't quite there. I used this one-liner to change the "cpan>" prompt to Bela Lugosi's famous line: "_I_am_Dracula__". It only accepts letters or underscores, and it only changes the prompt temporarily for that session. Happy Halloween!
#!/sw/bin/perl
use strict;
use warnings;
my $prompt = '_I_am_Dracula__';
system("perl -MCPAN -e 'CPAN::shell($prompt)'");