perl -e 'my $hashref = {
    normal_enemies => {
        cloud_guy => {
            attacktype => 'thunder',
            power => 4,
            hp => 5,
            },
        rain_man => {
            attacktype => 'water',
            power => 3,
            hp => 7,
            },
        flame_kid => {
            attacktype => 'fire',
            power => 6,
            hp => 4,
            },
        } };print map {$__=$_;join " ",$__,map {$_} keys %{$hashref->{
+$__}}} keys %$hashref'
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OUTPUT
normal_enemies rain_man cloud_guy flame_kid