Every Superhero must have a Secret Identity. The reasons are incredibly varied, but they have one.
This is often played for comedy when a Superhuman encounters someone they know in their Secret Identity and reacts according to how that person treats them in their downtime, usually with a Snub.
It is usually a case of an Alpha Bitch or Jerk Jock doing what they do best, being mean to someone just because they don't like them. Not realizing that the person they are actively victimizing is actually their favorite Superhuman and that there will be karmic payback for what they give out later. Sitcom Archnemesis can also play into this role.
Sometimes the subject may not have superpowers, they may just be famous and have fabricated their more well-known persona so that they can live an ordinary average life when not in the public view.
When played for drama, the superhero might actually be in genuine danger from a villain who hates them in their civilian guise, but indifferent to the cape, though in such cases overlap will likely occur when they either figure it out or simply get tired of the hero interfering with stuff that is none of their business.
- The villains Roman Sionis (Black Mask) and Thomas Elliot (Hush) both started out with grudges against Bruce Wayne personally rather than Batman, although the latter only turned to supervillainy after learning that they were the same person. In both cases it is an incredibly petty motive as they each came from wealthy families who knew the Waynes, and were jealous because the Waynes were a genuinely loving family while their own parents were abusive, so they target Bruce purely out of spite for things he had no control over.
- In Bruce Wayne: Fugitive, Wayne is framed for the murder of his girlfriends. The culprits each separately hate him both as Bruce AND Batman, but it is his Bruce Wayne identity that got him in this mess- Lex Luthor wanted revenge on Wayne since Luthor is now President and Wayne pulled out of his government defence contracts in protest, but he hired the assassin David Cain to do the job, unaware that Cain also had his own grudge both because Cain was one of the mentors Bruce had as a youth, and because the new Batgirl happened to be his daughter Cassandra Cain and he resented that she was working with Batman.
- In nearly every version of the franchise, Flash Thompson idolizes Spider-Man, but he and Peter Parker can't stand each other (at first - in the comics, they grow into good friends). Particularly played for laughs in the Ultimate Spider-Man cartoon: under the pretext of putting Flash somewhere safe, Spidey shoves him into a locker and then comments how petty it was, but fun!
- Not "hatred", but Anti-Villain Black Cat was attracted to Spider-Man and the feeling was mutual, so Spidey decided to unmask himself as Peter Parker...which horrified Black Cat because she only loved Spidey.
- The original Jem cartoon had a Two-Person Love Triangle between Jerrica, her boyfriend Rio, and her alter ego Jem. The Jem and the Holograms comic book reboot subverts that by having Rio initially hate Jem. He sees her as a diva who doesn't do anything for the band. Rio is completely dedicated to Jerrica and freaks out when Jem kisses him. He later reacts poorly when Jerrica reveals her secret to him.
- Legends of the Dead Earth: In Catwoman Annual #3, Bruce and Selina Wayne's teenage son Dick Grayson Wayne despises Batman and Catwoman. He regards them as murderers and thieves who should be brought to justice by Commissioner Joker. Dick does not take it well when he discovers that Batman and Catwoman are his parents.
- In Hop To It, it goes back and forth with Jack Smith/Rabbit. Rabbit is a Hero with Bad Publicity and a Destructive Saviour who is initially mistaken for an akuma and then for a villain in her own right after she causes a lot of damage to a Paris neighbourhood due a new power she can't control, but Jack, while initially an outcast (an American transfer student with a limited grasp of French), gains some popularity from her classmates after helping save Adrien from an akuma out of costume. On the other hand, while Ladybug knows that Rabbit is a good person, Marinette hates Jack out of misguided jealousy, believing she's interested in Adrien. When Marinette finds out Jack has a boyfriend back in the US, she apologises for her behaviour and she and Alya (who has since become a Rabbit supporter) make friends with her - just in time for Rabbit to screw up again and lose a lot of Ladybug's trust in her. However, it seems Ladybug may have forgiven Rabbit by the end of chapter 9, inspired by Jack's forgiveness of Marinette.
- Gets an amusing Lampshade Hanging just before before Rabbit first meets Chloé - "Maybe they could start fresh. It would be pretty funny if Chloé adored her as a superhero." - and then subverted when she hates Rabbit just as much as Jack.
- Dark Savior features a Selina Kyle actually hostile to Batman whom she derides as a self-righteous twit encouraging bored maniacs to escalate. Their relationship started as the traditional sexually charged chase-around but it soured after they had sex and seventeen-year-old Selina found herself pregnant - hinting she may resent Batman a tiny bit for forcing her to deal with an upcoming baby.
- In Batman: Anarchy for All, Lonnie Machin is a Batman fanboy but loathes Bruce Wayne, whom the teen believes is no different from his chronically absent and emotionally abusive father, a Wayne Enterprises board member. When Hugo Strange relates his knowledge of Batman's secret identity, Anarky has his second largest breakdown of the book, unable to accept the very idea that his idol and "Gotham's fattest leech" could be one and the same.
- The Legend of Zorro: Alejandro's son Joaquin idolizes Zorro, but thinks his own father is a loser.
- Cybergirl: The Buxton twins are quite specific in explaining how close friends they are with Cybergirl, to Ashley and her Secret Keeper friends. Jackson plays along with the secret joke, asking them to get him Cybergirl's autograph. Later in the episode, when Cybergirl comes to rescue their mother, the twins greet her with great enthusiasm and she brushes past them without even acknowledging their presence. What they don't see is her smile after she delivers the snub.
- Hannah Montana: Amber and Ashley, who bully Miley, idolise Hannah.
- The Thundermans: Mrs Wong is in the Thundergirl fanclub, but has extreme disdain for Phoebe Thunderman.
- The Flash (2014):
- Captain David Singh, while he respects Barry's capabilities as a CSI, is still always critical of him, especially when it comes to Barry's tardiness. However, Singh is also one of the Flash's biggest supporters even in the latter's early years.
- In Season Four, during his debut episode, Barry Allen's Sitcom Arch-Nemesis Ralph Dibny reveals that he is a fan of the Flash. During the climax when Barry reveals his identity to him, Ralph starts lamenting over how he has to hate the Flash now.
- American Dragon: Jake Long: A doubles version, Jake and Rose both have secret identities who are each other's sworn enemies, but are dating. Eventually subverted when Jake and much later, Rose find out who they were fighting all this time and then agree to let the animosity end.
- Batman: The Animated Series: In Night of the Ninja, a ninja comes to Gotham to kill Bruce Wayne because of a grudge that developed years ago when Bruce was training to be Batman. This leads to him actually fighting Batman, and he recognises the fighting style and realises that they are the same person.
- Batman Beyond: Matt McGinnis is a big fan of Batman, and regards his big brother Terry as a boring twip who's hardly ever around.
- Big Hero 6: The Series: Karmi is in love with BH6Hiro, but really despises Hiro Hamada.
- Danny Phantom:
- Danny Fenton is severely bullied by Dash Baxter who is one of Danny Phantom's biggest fans.
- Dr. Dimensionpants: Rebecca is in love with the title character but not with Kyle, who is his secret identity.
- El Tigre: Manny is quite close to Zoe Avers, but completely ignores her supervillian identity of Black Cuervo. Ironically despite all the emotional torment and sometimes physical violence received, she genuinely loves him. A subversion because Manny is publicly known to be El Tigre, but Zoe has a secret identity, which leads to an incredibly complicated relationship.
- Miraculous Ladybug
- Chloe Bourgeois is one of the biggest Ladybug fangirls in the cast, but has a mutual hatred for her alter ego Marinette. In various episodes where she gets to meet Ladybug personally (usually after creating the Villain of the Week) and keeps hugging her, Ladybug's response every time is to push her away with a disgusted expression and some light slapping. It remains to be seen how this dynamic will be affected when Chloe gets the Bee Miraculous in season 2.
- Subverted in "Lady Wifi" where Cat Noir sees Chloe cosplaying as Ladybug and is horrified at the possibility he may be crushing on her. Naturally, he is tremendously relieved when the actual Ladybug shows up to meet him.
- My Life as a Teenage Robot: Jenny initially falls in love with the Silver Shell, but can't stand Sheldon, even though he made up the Silver Shell identity to repulse her and make himself seem better by comparison. This is eventually reversed, as she ultimately at least thinks of Sheldon as a friend, but when Sheldon tries to date her as the Silver Shell, Jenny comes to dislike his alter-ego (which cause Sheldon to mostly abandon it).