My ...favorite present from a predecessor was about 120kB of completely uncommented Perl of the "There's More Than One Way To Do It, So We Should Use The Most Opaque And Obscure Way Available" school of Perl coding. It looked like someone had puked up a half-digested sendmail.cf. The guy apparently didn't understand how to include external libraries in Perl, either... there was one massive block of code that was inlined in at least three different places. And not a single comment to help illuminate what sort of delusions were passing through his brain when he wrote the thing. I diagnosed it more by watching its data files and seeing what happened when I poked it than by trying to unravel the knot of its code.

And I ultimately used the Gordian solution... just tossed the whole mess and wrote a replacement from scratch. Mine was fully commented, a lot more clearly written, and about a third the size, even with the comments and the more verbose coding style. And it cut out about three stages of the process that served no real purpose and had previously required manual intervention, including (I kid you not) a bit where the data was packaged up and FTPed to my predecessor's new company to be processed and returned. (I was working for public television, and it was our broadcast schedule to be posted on our website, so it's not like this was confidential information or anything. But still. What. The. Hell.)