Ass Pull: Sam Bradley, Jr. gets revealed as baby Helena's father in the post-One Year Later comics after numerous hints and teases (most obviously the name) that her father was Bruce Wayne. Not only did Selina and Sam barely have a relationship (the night of Helena's conception essentially involves Selina acknowledging Sam finds her attractive and having sex) but dedicated fans who did the math on how old Helena was supposed to be, as well as when she supposedly was conceived, noted it made no sense for him to be the father.
Complete Monster: The Film Freak/"Edison" is a disturbed young criminal who values cinema more than human lives, and is determined to make the greatest film on human suffering as possible. In his first outing, Film Freak allies with Angle Man and kidnaps Catwoman's infant daughter, threatening to torture and kill the baby while filming it and Catwoman's agony at the crime. Escaping justice, Film Freak goes on a killing spree of people just for not knowing movie trivia, uses several people as his pawns only to then kill them, and slaughters his way into a TV station to threaten all of Gotham. Film Freak's final plan is to detonate an atom bomb, kill all of Gotham, and irradiate the entire area, all as a movie reference and to make himself famous.
The majority of fans tend to ignore the revelation that the father of Selina's post-Crisis daughter Helena was Sam Bradley, Jr. and not Bruce Wayne, with many considering the reveal an Ass Pull at best. And that's including those who like to acknowledge the existence of that storyline at all.
Fan perception of Selina's protégé Shoes turned into a mess after it was revealed she's really Lian Harper, only a Lian suffering from total amnesia of her life with her father, the Titans, and the Arrows thanks to her mother abandoning her in Gotham City and letting everyone believe she was dead. While fans spent over a decade demanding Lian be brought back, that DC chose to do so by aging Lian up, stripping her of her personality, separating her from her family, and making her a supporting character for a character she had no prior connection with, has been heavily debated and criticized. While fans are happy that Lian's back, they're not happy that she's "Shoes" and choose to think they're not the same person.
Narm: One of the few things everyone can agree on regarding Lian Harper being Cheshire Cat is that "Shoes" is a stupid name for the character.
Newer Than They Think: Despite being her iconic outfit, she's only worn a black catsuit in the comics since her redesign by Darwyn Cooke in the early 2000s. Prior to that in the post-Crisis era, she usually wore a purple catsuit, and her Golden Age and Bronze Age versions often wore dresses, or leotards over tights. However, her Batman TV incarnations all did wear black leather catsuits, as did her incarnation from Batman Returns, and that probably created the image.
Unexpected Character: It's safe to say that no one was expecting to see SNOWFLAME in comics again, much less in Catwoman's book. Likewise, no one expected her teenage protégé Shoes to actually be Lian Harper considering the last time anyone saw her she was several years younger and dead.Similarly no one probably expected Red Claw to appear at all.