Continuity mistake: In the scene where Marcus reads the comic showing the origins of Big Daddy and Hit Girl, we see a closeup of the last but one page, but when Marcus holds the comic book up to Damon in the next shot, the page is completely different to what it was before.





Answer: It's a modified version of the "Tra La La Song" from the Banana Splits TV series of the 1960s. http://en.wikipedia.org/wiki/The_Tra_La_La_Song_(One_Banana,_Two_Banana).
Jeff Swanson