Deliberate mistake: When the fight first begins on deck of the sub, a henchman jumps from the hatch and picks up a wrench that was lying on deck. If the sub just surfaced, where did that wrench come from?
Continuity mistake: When the Batmobile is going to park (before the bomb scene) there is a sign saying "Mobey Dick Parking Only". When he is later carrying the bomb and passes by the Batmobile the sign is not there.
Trivia: Cesar Romero refused to shave his moustache for the role of Joker, so it's still visible under his makeup.
Answer: The Riddler doesn't sing at all. He yells to the henchmen on board, "Prepare to repell boarders!" He does it in a almost musical way, true, but there's no song.
CCARNI ★