Which version of Perl is it running on? Straight from the download link, I got this:

~$ perl5.10.1 obfu
syntax error at obfu line 2, near "package gn 4.242"
syntax error at obfu line 3, near "}}"
syntax error at obfu line 3, near "ghs:sub dx"
syntax error at obfu line 4, near "$i}"
syntax error at obfu line 10, near "}}"
Execution of obfu aborted due to compilation errors.
~$ perl5.16 obfu
offee
offee
offee
offee
offee
offee
offee
...
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