My song for the Harry Potter fandom is to the tune of Happy Birthday.
Line 1= my lyrics, line 2= original.

1) Harry Potter is a wizard
2) Happy Birthday to you
1) and Voldemort killed his parents
2) Happy Birthday to you
1) Now he has a scar and goes to Hogwarts
2) Happy Birthday dear (so + so)
1) And he stopped the dark lord again!
2) Happy Birthday to you...

Sorry it sucks, but I hope I'm still in.