my $string = "It's a cat and mouse game.";
$string =~ s/(.)/$1 x (1 + rand(3))/ges;
print "$string\n";

$string = "It's a cat and mouse game.";
$string =~ s/([A-Za-z])/$1 x (1 + rand(3))/ges;
print "$string\n";

##</code><code>##

IIIt'''s  a  cccat annddd mmoooussee gaammeee...
IIItt'sss aa cccaaattt and mmoouusee ggaame.