While the show itself is great, there were lots of special ideas that never saw the light of day (some did, but in a different manner). Here they are:
- An unfinished episode "The Gun Story", told from the perceptive of the gun used to kill Thomas and Martha Wayne. It would have revealed that Joker was the killer.
- A two-parter "Masks", where Batman reconnects with a past love who is connected to a murderous new vigilante.
- Became the feature film Batman: Mask of the Phantasm .
- An episode "Vigil", where Alfred Pennyworth recalls when Bruce first became Batman.
- Became the flashbacks in Batman: Mask of the Phantasm.
- An unnamed episode where Batman meets Nocturna and temporarily becomes a vampire.
- Loosely adapted into the live-action Batwoman series.
- An episode involving Poison Ivy seducing Swamp Thing.
- Expanded on in Batman Adventures, Vol. 2 #16.
- A follow-up to Batman & Mr. Freeze: SubZero called Batman: Arkham, in which Batman and Robin must control a massive take-over at Arkham Asylum.
- Became a successful line of video games, known as the Arkhamverse.
- An appearance by the Creeper.
- Appeared in The New Batman Adventures.
- An appearance by Firefly.
- Appeared in The New Batman Adventures.
- An appearance by Black Canary.
- Appeared in Justice League Unlimited.
- An appearance by the Huntress.
- Appeared in Justice League Unlimited.
- A Robin design more akin to the current outfit of Tim Drake with an Elvis-style hairdo.
- Penguin being a "legitimate businessman" with a more human appearance.
- Appeared in The New Batman Adventures.