Actually, Batman Continues didn't exist. Batman Forever didn't start out as a Tim Burton project. It was always Joel Schumacher's baby. Tim Burton's only involvement with Batman Forever was to hire his friend Joel Schumacher as director, and help out hiring Lee and Janet Scott Batchler as the screenwriters, with Akiva Goldsman doing revisions. And it was Joel Schumacher who wanted Michael Keaton to come back to play Batman, Rene Russo to play Dr. Chase Meridian, and Robin Williams to play The Riddler, since they already had Tommy Lee Jones to play Two-Face. History shows the three film stars ended up not doing Batman Forever, and Val Kilmer stepped into the role of Batman, Nicole Kidman as Chase Meridian, and Jim Carrey as The Riddler.
The Riddler with a question mark shaved into his head was actually an idea from Jim Carrey. An old Empire interview revealed that Carrey played around with an idea of shaving a question mark into his head, but that didn't go through, because Carrey was going through a divorce court at the time, and he cannot show up in court with a question mark shave on the back of his head. And The Scarecrow, Michelle Pfeiffer's Catwoman, and Poison Ivy were not in any draft of Batman Forever, because they already had Tommy Lee Jones as Two-Face, and Jim Carrey as The Riddler.