The naked mole rat is a real thing, but not a Batman villain.

Sweet Tooth appeared in only one episode of The New Adventures of Batman in which he tried to change Gotham's water supply into chocolate and blackmail the city for five million dollars which he doubled to ten million after Robin made a pun about his weight.

Sherman Fine, also known as The Broker, provides hideouts and secret lairs for Gotham City's criminals -- at a price. He's found places for the Joker, Catwoman, Mad Hatter and others.

Thomas and Martha Wayne were walking home from the Monarch Theater with Bruce, when they were gunned down by a mugger who wanted Martha's pearl necklace.

A sign outside the Batcave says "14 miles to Gotham City".

After the Riddler spiked Batman's orange juice and abducted Robin, the caped crusader tried to pursue in the Batmobile, but a pair of Gotham cops wisely confiscated his car keys.

When Jack Nicholson accepted the role of the Joker in 1989's Batman for $6 million instead of his then-average salary of $10 million, part of the deal was that Nicholson would earn a percentage of the film's total earnings, including merchandise sales. In all, for his work as the Joker, Nicholson is said to have pocketed over $100 million.