The Batcave's giant penny. Despite being the most infamous part of the cave's background, Batman got it from an early, absurdly minor foe of his called the Penny Plunderer. Said villain has never made a comeback, but his penny is too iconic to drop at this point, so most later incarnations starting with Batman: The Animated Series kept it but attributed it to Two-Face instead.
Robin: As comics get Darker and Edgier, a Kid Sidekick is more and more obviously an unethical endangerment of the poor kid, especially since letting them actually die is nothing new. Why is there still always a Robin? The reasons vary, but they usually come down to the kid being set on a dark and dangerous path anyway, and Batman taking them under his wing to make sure the kid can actually survive in a place like Gotham and, in some cases, be a proper hero instead of crossing the line. Young Justice (2010) touched on the idea when Wonder Woman calls Batman out on exactly this, questioning if he's trying to make Dick into another Batman because he lost his parents, too, but Batman says that he instead did it to give Robin a better sense of closure so that he wouldn't become another Batman.
Dick Grayson: This is how the original Robin's origin story was reimagined, with Dick trying avenge his Death by Origin Story-victim parents on his own anyway before Batman took him in. It was an important part of the backstory of Nightwing (Rebirth) with the introduction of Raptor, a fellow Romani and old friend of his mother: once thieves, she went straight while Raptor didn't, and he sought to raise Dick his own way but Bruce got to him first.
Jason Todd: He was a delinquent who Bruce wanted to help, knowing that he had the potential to be a hero but would more than likely end up as just another petty criminal if Bruce didn't intervene. It's also implied that Bruce used him as a Replacement Goldfish for Dick after their falling-out.
Tim Drake: The role of Robin was reimagined somewhat differently with Tim, with Robin stepping in to save Batman from going down a dark path rather than the other way around. After Jason Todd's death, Batman's borderline-instability could easily turn into a He Who Fights Monsters case if he didn't have someone to keep him down to Earth; Tim took up the mantle (after first unsuccessfully trying to persuade Dick to return) out of the belief that "Batman needs a Robin."
Damian Wayne: Raised by a multinational secret society to be the perfect assassin, he seemed all set to inherit the throne of his grandfather, Ra's Al Ghul. However, he instead chose to follow the footsteps of his father, Bruce Wayne. Damian can and has killed many full-grown and trained men, so his time as Robin is more to teach him morality and compassion.
Batman famously refuses to carry a gun under any circumstances, even though he doesn't have any superpowers, and his job would presumably be a lot safer if he at least kept a pistol around for self-defense. For most of his history, this was largely because the Comics Code Authority severely limited portrayals of violence in comic books, so it became a general rule that superheroes just don't carry guns.note While Batman did carry a gun in a few of his very first appearances, these are generally dismissed as Early-Installment Weirdness. These days, that's no longer the case; not only is the CCA defunct, but superhero comics are also now marketed to adults almost as often as children, and superheroes who carry guns (like Cable, the Punisher, and even Batman's former sidekick Red Hood) are fairly common. Today, though, Batman's hatred of guns is a well-established part of his characterization rather than a standard superhero trope. He could get away with carrying a gun if he wanted, but he refuses to stoop to criminals' level by committing murder, and he prefers to prove his superior physical ability by beating them the old-fashioned way. Sometimes it's linked specifically to Batman's grief for his parents, who were killed by a gun. The act of using a gun is so painful for him that, at least in one instance, he quits after realizing that he's no longer capable of fighting crimes without a gun.
Batman Forever applied this trope to the iconic Robin outfit, which had become a source of some mockery for being a bright red, green, and yellow outfit that contrasts sharply with Batman's black, blue, and grey outfit. The film depicts the traditional Robin outfit as the uniform of the Flying Graysons in the circus, so when Dick Grayson becomes a costumed fighter in his own right, he wears a suit of body armor just like Batman's, but bearing the colors of the circus uniform to honor his family, and the colors are muted and metallic to be less gaudy.
Catwoman uses a chain as a flail rather than the traditional bullwhip.
The set of three scallops on Batman's gauntlets are simple straps instead of blades awkwardly positioned to defend against knives.
The Riddler's gimmick of leaving behind riddles that when solved reveal his plans is reimagined as him trying to covertly communicate with Batman because he believes they are secretly on the same side. Furthermore, almost all his riddles actually relate to crimes committed by other people who the Riddler wants Batman to expose - The only exception, the riddle that reveals his plan to bomb the flood wall, was meant to give Batman enough warning to get to safety first.
Western Animation
Beware the Batman uses the D-list and extremely80s villain Magpie as a recurring character, but she's been given a 21st century makeover so that she now resembles a flashy, modern pop starlet like Lady Gaga rather than a hair metal groupie.
Batman Beyond features a reimagined version of Ace the Bat-Hound. First introduced in the comics during the campy Silver Age (when animal sidekicks were something of a fad in superhero comics), Ace was originally a masked crimefighting dog who occasionally accompanied Batman and Robin on their adventures. The show keeps the general premise of Bruce Wayne having a canine companion—but instead of Ace being his sidekick, Bruce just adopts him after retiring from crimefighting, giving him some much-needed companionship in his old age following the death of Alfred (by this point, Bruce has long since fallen out of touch with his old friends from his days as Batman). Notably, though, the showrunners still find a way to make Ace every bit as heroic and formidable as he was in the comics, giving him his very own centric episode where it's revealed that he was adopted by Bruce after escaping from an illegal dogfighting ring, leading to him helping Terry McGinnis bust said dogfighting ring after he recognizes his former handler's scent and leads Terry to his hideout. He even comes to Terry's rescue in the field a few times, including in his battle against the resurrected Joker. Good dog indeed.
as a recurring character, but she's been given a 21st century makeover so that she now resembles a flashy, modern pop starlet like Lady Gaga rather than a hair metal groupie.