Continuity mistake: In the scene where the family are singing an African song, they all point their arms up to the ceiling yet in the next shot, Lois's arms are immediately cupped and pointed downwards - you don't see her moving her arms to that position.
Continuity mistake: When Chris tells Meg not to rake the two leaves because they are his friends, one leaf is brown and the other is yellow. After Meg picks them up and crushes them, they're both brown.
Other mistake: When Lois knocks out the karate master, if you look in the stands, behind Peter, there is a person without a nose.
Revealing mistake: When Peter runs across the dock after getting out of the boat, a large chunk of his body is missing.
Continuity mistake: When Stewie is thrown from the swing and lands in another little girl's stroller, the inside is suddenly much larger after Stewie lands in it when the camera changes angles to how big it was when he was flying towards it. It suddenly has enough room for Stewie to be lying beside the girl with room to spare while she is still in the center, when it was barely big enough for her alone before he landed.
Chosen answer: It's a real song called "Elvira". Originally by Dallas Fraizer in '66, however, this version seems to be the Oak Ridge Boys cover version. However, the mega lesbians skip the verse and just sing the chorus after the opening line.
Bishop73