Criminals are a cowardly and superstitious lot. So I must be able to strike terror into their hearts. I must be a creature of the night, black, terrible.
The Batman is a scary man. Dressing like a sinister combination of Dracula and a giant bat, this vigilante's single greatest power (no, not money, Flash) is his ability to strike fear and dread into the heart of common criminals. That's pretty heavy stuff, even before we get onto the Jujitsu, the Goth car and the batarangs.
Another thing about Batman: he has perhaps the greatest rogues gallery in all of comics. When your hero is as scary as the Bat himself, it stands to reason that his enemies tend to be more than up to the challenge. After all, who but the most terrifying criminal dare stand up to a lethal ninja dressed almost entirely in black? You'd have to be pretty crazy, right?
Well just wait until you get a load of these guys. Sometimes even a Batman falters when faced with an army of dangerous madmen, sinister monsters and legendary supernatural horrors. A scarecrow, a Mad Hatter and a murderous clown (who, for the purposes of variety, has been restricted to but a couple of outings on this list).
Between the Bat himself and his enemies, Batman stories have a tendency to get scary, running the bat-gauntlet from spooky to downright terrifying.