One great fanfiction could be about Catwoman's origin story within the animated series' universe. Maybe she starts as a small - time thief in Gotham's slums and gradually rises to become the iconic cat burglar we know. She could have a complex relationship with Batman that is explored more deeply, like her internal struggle between her feelings for him and her life of crime.
Batman: The Animated Series is considered to be a reasonably faithful adaptation of the comics. It keeps the key characters and major plot points, while also adding some unique touches to make it stand out as an animated series.
In many Batman and Robin fanfictions where Robin is injured, it often leads to Batman becoming more determined to catch the villain. For example, in some stories, Robin gets injured during a fight with a new, powerful enemy in Gotham. Batman then uses his detective skills to track down the bad guy while also taking care of Robin. He might call in Alfred for help with Robin's injuries. This kind of situation shows the deep bond between Batman and Robin and how they rely on each other in tough times.
An interesting idea is to write a story where Catwoman discovers a secret about Batman's past that even he doesn't know. This could lead to a strange alliance between them as they both try to figure out what the discovery means. It would also add a new layer to their relationship.
One idea could be creating an original character (OC) who is a new villain in Gotham. This OC could have a unique power, like the ability to control technology. They would target Batman's high - tech gadgets and try to disrupt his crime - fighting efforts.
Not that I'm aware of. Comics come and go, and it's possible it's no longer in production or readily available. You could search on dedicated comic forums or websites for more accurate details.