You can also just say rand(@password_chars) and get rid of the $num_char variable entirely.

Also, as long as your are hard coding the iteraction as 'for (1..8)' you can gain even more speed by just doing it like this: (forgive my shortening of password_chars)

sub Pass {
  return 
    $p_c[rand(@p_c)] .
    $p_c[rand(@p_c)] .
    $p_c[rand(@p_c)] .
    $p_c[rand(@p_c)] .
    $p_c[rand(@p_c)] .
    $p_c[rand(@p_c)] .
    $p_c[rand(@p_c)] .
    $p_c[rand(@p_c)];
}
[download]

You could even take out the "return"!