I bred these critters (composed of 4 flavors of gene) overnight using a modified version of gumpu's code at Genetic Programming or breeding Perls. They're 24 genes long because I was going to obfuscate a map of them in a string the same length as "Just Another Perl Hacker" but the new year is almost upon us :)

perl -le '$_+=$_++;$_+=--$_;$_+=$_--;$_+=++$_;$_+=$_++;$_+=$_--;$_+=$_
+--;$_+=--$_;$_+=$_--;$_+=$_++;$_+=++$_;$_+=++$_;$_+=--$_;$_+=$_--;$_+
+=--$_;$_+=$_++;$_+=$_--;$_+=--$_;$_+=$_--;$_+=$_--;$_+=$_++;$_+=--$_;
+$_+=++$_;$_+=--$_;print'

perl -le '$_+=$_--;$_+=$_++;$_+=++$_;$_+=$_++;$_+=$_--;$_+=--$_;$_+=$_
+--;$_+=$_++;$_+=$_++;$_+=++$_;$_+=$_++;$_+=--$_;$_+=++$_;$_+=--$_;$_+
+=$_--;$_+=++$_;$_+=$_--;$_+=$_++;$_+=$_--;$_+=++$_;$_+=++$_;$_+=++$_;
+$_+=--$_;$_+=--$_;print'

perl -le '$_+=$_--;$_+=++$_;$_+=$_--;$_+=$_++;$_+=++$_;$_+=$_++;$_+=--
+$_;$_+=$_--;$_+=++$_;$_+=$_--;$_+=++$_;$_+=$_++;$_+=$_--;$_+=$_++;$_+
+=$_--;$_+=--$_;$_+=$_--;$_+=$_++;$_+=$_++;$_+=$_++;$_+=--$_;$_+=--$_;
+$_+=--$_;$_+=--$_;print'

perl -le '$_+=$_--;$_+=++$_;$_+=$_--;$_+=++$_;$_+=$_++;$_+=--$_;$_+=$_
+++;$_+=$_--;$_+=--$_;$_+=$_--;$_+=++$_;$_+=++$_;$_+=--$_;$_+=$_--;$_+
+=$_--;$_+=$_--;$_+=$_--;$_+=--$_;$_+=$_--;$_+=--$_;$_+=++$_;$_+=$_--;
+$_+=++$_;$_+=++$_;print'
[download]

The four arbitrary gene types allow for 2002-printing critters of length ten:

perl -le '$_+=++$_;$_+=++$_;$_+=++$_;$_+=++$_;$_+=$_++;$_+=++$_;$_+=++
+$_;$_+=++$_;$_+=--$_;$_+=--$_;print'
[download]