This is my second attempt at Perl Golf. Although my score (281) sucks, I wanted to post my code because I had a hard enough time just getting it to work at all. :-) I know I could make my code more concise, but I've run out of time! I've got to actually get some work done today!

My free subs:

sub a {
    print shift;
    my $answer = <STDIN>;
    chomp $answer;
    return 1 if $answer =~ /y/i;
    return 0;
}

sub t {
    print "What is your animal?\n";
    my $answer = <STDIN>;
    chomp $answer;
    return $answer;
}

sub i {
    my ($g, $u) = @_;
    print "What is a question that is true for $u, but false for $g?\n
+";
    my $answer = <STDIN>;
    return $answer;
}

sub w {
    print "Do you want to continue?\n";
    my $answer = <STDIN>;
    chomp $answer;
    return 1 if $answer =~ /y/i;
    return 0;
}

sub g {
    my $animal = shift;
    print "Is your animal a";
    print "n" if $animal =~ /^[aeiou]/;
    print " $animal?\n";
    my $answer = <STDIN>;
    chomp $answer;
    return 1 if $answer =~ /y/i;
    return 0;
}
[download]

My free initialization:

my @t = (
    [
        undef,undef,
        ['cat','giraffe',"Is your animal larger than a breadbox?\n"]
    ]
);
[download]

And my long-winded (281) solution:

sub r{my$t=shift;my$x=a($t->[2][2]);$t->[$x]?r($t->[$x]):return $t->[2
+][$x]}sub
n{my$t=shift;for(0,1){if($t->[2][$_]eq$b&&!$t->[$_]){$t->[$_]=[undef,u
+ndef,[$b,$
a,$q]];return 1}last if$t->[$_]&&n($t->[$_])}}while(1){$b=r($t[0]);if(
+!g($b)){$a
=t();$q=i($b,$a);n($t[0])}last if!w()}
[download]