I guess while we are beating this thing to death...
I find this pretty easy to read... List::Util is great module.

#!/usr/bin/env perl

use strict;
use warnings;
use Data::Dumper;
use List::Util qw(uniq);

my %hash;

while (<DATA>) {
   
    my ($animal, $part) = split /\s+/;
    push @{$hash{$animal}},$part;
}

@{$hash{$_}} = uniq @{$hash{$_}} for keys %hash;

print Dumper \%hash;

__DATA__
bird beak
bird beak
bird claw
bird wings
bird feathers
snake fangs
snake scales
snake fangs
snake tail
[download]