The Caped Crusader's nemesis has been given a redesign for issue #13 after having his face removed in Detective Comics #1, a move which the scribe says has made the character "scarier".
Snyder told Newsarama: "He really is going to, obviously, have a new look. At the same time, we want it to echo his iconic look. So it's Joker in a much more horror movie fashion.
"Without giving too much away, you will see the iconic face and the grin, and he might look a little bit different and scarier. But you'll find that he's still himself at his core. And he's really here in his blood-stained clothes going to work."
Artist Greg Capullo echoed Snyder's sentiments, warning readers that they may be shocked by what they find in Batman #13.
He said: "I would say that if you have any kind of heart conditions, or any kind of medical issues that could cause seizures or what-not, that you should check with a doctor prior to buying this story arc, because we don't want to be responsible.
"DC does not want to be responsible for any fatalities or hospitalisation or young or old people who may encounter this story and it just simply be too much for their system."
Batman #13 will be released in October.