in reply to hidden functionality

Since you asked ...
SPOILER follows.
Add the following before your triple eval.
print; print "\n>>>>\n"; print eval $_; print "\n>>>>\n";
Your $_ is first uudecoded and then packed from hex.
After the first eval you have:
my$c;$_="7072696e7420224a75737420616e6f74686572205065726c206861636b657 +25c6e223b"; while(m((..))sg){$c.=chr hex$1;}return$c;
A hex string converted to plain text. Why not using pack then?
return pack "H*", $_;
Anyway, the hex string contains the plain
'print "Just another Perl hacker\n"'
Cheers.
cchampion