Animal::speak('Cow'); 

##</code><code>##

use warnings;
use strict;

package Animal; {
    sub speak {
        my ($class) = @_;
        if ($class eq 'Cow'){
            print "$class says moooo!\n";
        }
    }
    sub run {
        my ($class) = @_;
        print "$class is running away!\n";
    }
}

package Cow; {
    our @ISA = qw(Animal);
}

package Rooster; {
    our @ISA = qw(Animal);
}

package main;

Cow->speak;
Rooster->run;

##</code><code>##

Cow says moooo!
Rooster is running away!