Given enough time I might be able to come up with a replacement for the whole song. I am only mildly creative. Some friend of mine could do it in no time - the one they did for Bowie's Space Oddity is awesome - though it's an inside joke for the forum we're all on because it refers to one specific member.
In college we did one for one of our EE professors. The guy all the upperclassmen warned us was such a horrible professor - he ended up being my favorite and I took every class of his I could, even though I was mostly leaning digital I took his op amp course, which was awesome - one of the few notebooks I've saved from all those years ago even though the last time I designed something with op amps was probably that class. He was tough, but very fair - if you blew off work and failed tests, you got what you deserved, if you put forth effort and showed up and sough out help when you needed it, he made every effort to make sure you could pass. So one night, we're all in a study lounge studying for the final, just before winter break. And we came up with this whole parody of Santa Claus is Coming to Town. = "Uncle Karl is Teaching Today" (his name was karl, duh!). 3 whole verses and chorus. So we got the idea to anonymously distribute it in class. We knew he hung out a lot with one of our other professors, so we put a copy of the song and a note telling the other prof what we intended and for him to just mention it in class one day if he thought Prof Holzinger would take it as a joke, or if he would be pissed. If he would be offended, we would simply drop it and nothing more would be done. We slipped it into his mailbox with no names or anything. A week or so went by and nothing out of the second prof. We thought either they knew it was us and were really pissed, or something of that sort. Then one day as everyone was packing up and leaving the lecture hall, the second prof called out that he had one more thing - he said he got something in his mailbox the other week and that it should be ok to do what it said! So we had a few hundred copies printed up, and Prof Holzinger had a tendency to have some assistant bring in a stack of handouts and put them up front and expected us to just take them, so we recruited a freshman we knew to carry the stack in one morning. But for some reason, no one was taking them - so my friend goes down and gets one, and that started the flood. The lecture hall is buzzing as people are reading this. Prof Holzinger walks in, sees the pile of papers and looks questionably at it, picks one up, looks it over, and stuff it in his briefcase. His expression never changed, he never said a word - we were thinking we were now dead, that they DID know it was us, and he's pissed off about this song. Never heard a word about it, that was sophomore year, one of our first EE classes. After finals senior year, I happened to be walking past his office and he asked me to stop in if I had a minute. We mostly chatted about my opinions on the EE department, and the education experience there and so forth. Somehow the topic of the song came up, and he said "I knew it was you guys all along. That was pretty funny." So much for putting one over on this guy. Next time I'll tell you about the sign in sheet and camera...