#!/usr/bin/perl -l

use strict;
use warnings;
no warnings qw /syntax/;

my %HoA = (
    simpsons    => [qw /homer marge bart/],
    flintstones => [qw /fred barney/],
    jetsons     => [qw /george jane elroy astro/],
);

print for sort map {my $name = $_; map {"$_:$name"} @{$HoA {$name}}} keys %HoA;