When comic books were first released, the heroes were usually depicted as adults. They were considered as the ideal; the prototypes of humanity that we should all strive to become. Not too long afterwards, publishers discovered that the main demographic for comic books was children and they wanted to feature in the stories as well. Understanding and listening to what the readers wanted, sidekicks were introduced as a form of wish fulfilment for the fans. Suddenly, Robin became as popular as Batman, and teams such as the Teen Titans found more favor than the established (and older) Justice League.
Time waits for no man or woman, though, and we've witnessed many of these heroes grow up over the decades. Sure, they haven't exactly aged at the appropriate rate – otherwise, most of them would be senior citizens by now – but we've seen how a youngster like Bucky Barnes turned into the Winter Soldier and other heroes followed suit. With comic books respecting timelines as much as Twitter users do civil conversation, there's always the possibility that characters can regress or age in a matter of months. Still, there are a few DC and Marvel characters who grew up and maybe shouldn't have.
20 TIM DRAKE
As the third person to claim the Robin mantle, Tim Drake delighted fans with his combination of brains and detective skills. While Dick Grayson and Jason Todd might've been overall better fighters, Tim was the smartest of the pack – even challenging the Dark Knight's intellect on more than one occasion.
Like the other Robins, though, he eventually grew up and decided to leave the Batcave for greener pastures. It left a sidekick gap for Batman, which was filled by Damian Wayne. While many fans of Tim will defend his aging as a necessary evil, his storylines haven't exactly blossomed since he left the Caped Crusader's side.
19 KITTY PRYDE
When Kitty Pryde joined the X-Men, she was considered the youngest member of the group. Her popularity grew and she even took up the alias of Shadowcat. Much like the rest of the world, Kitty embraced Father Time and what the years had to offer her, including high-profile romances and a spot in the Guardians of the Galaxy team.
Like her brethren in the X-Men, however, Kitty has had a rough time on the pages as of late. Perhaps it's because of Marvel affording less time to Xavier's mutants as a result of Fox holding the film rights. Look, it's no secret that the X-Men stories have been poor in comparison to what's been done before.
18 WALLY WEST
For a generation, Wally West is the only Flash they recognize. Of course, this happened in the period that DC offed Barry Allen in Crisis on Infinite Earths and he only reappeared years later. Yet, for others, Wally is remembered as the original Kid Flash and an important member of the Teen Titans.
In fact, looking at the current DC continuity, Wally seems a bit lost right now, as there's another Wally in the Teen Titans and Barry is the Flash. So, where does he fit into everything? Quite frankly, we don't have the answer to this. Maybe Wally should've remained as a teenage hero in another timeline.
There's a reason Spider-Man is one of the most popular superheroes in the world. For many children, Peter Parker embodies what's possible for them. He was a typical teenager, with regular problems, until a radioactive spider bit him and changed his life.
Over time, we've seen Peter finish high school, college, and start his own life. He's married and divorced Mary Jane Watson; plus, he had Doctor Octopus take over him in a bodysnatching arc known as Superior Spider-Man. Somewhere down the line, though, Peter stopped being Peter. The stories were far removed from where they began and it's no surprise that the younger Mile Morales is now overtaking him in becoming the most popular Spider-Man.
16 DAMIAN WAYNE
In all fairness, Damian Wayne has remained the same brat in regular continuity. He's still as annoying as the day he first showed up, and there's no sign that he'll ever change. Fortunately, DC hasn't altered his age too much and he's still seen as a teenager.
There have been a few stories, though, where we've met an older Damian. Sadly, the future doesn't turn out too well for him. In the Batman Beyond comic book, he became the new Demon's Head and we also saw him become the Punisher version of the Dark Knight in Batman #666. You'd think that with more maturity, he'd change his attitude, but nope.
15 HOPE SUMMERS
Ah, another example of the X-Men timelines messing everything up. When we were first introduced to Hope Summers, she was a child who was destined to save mutants and humankind. It was a massive role and it was obvious that there would be time jumps to meet an older Hope.
As expected, though, the time jumps didn't do much for her growth. It's a case of where the promise of Hope was more exciting than seeing her try to fulfil her destiny. While the character is relatively new to continuity, having only been introduced in 2007, there's already a risk that her best years might be behind her.
14 DONNA TROY
Wonder Woman's clone, Donna Troy, has had quite the renaissance. Not only is she the leader of the pack in the current Titans comic book run, but she's also been portrayed for the first time in the live-action world by Conor Leslie. It's the Amazon's world right now!
Still, it's evident that Donna will go back into the shadows once Dick Grayson regains his memory. Her leadership of the Titans team is only temporary. In fact, it could be argued that Donna's greatest days will be the time she was in Teen Titans. Will she be able to stand out on her own in a world that already has Wonder Woman?
If it wasn't for Fox pushing out The New Mutants several times now, Maisie Williams' Wolfsbane could've become the latest 'it' character in comic book movies. Especially since she's a 'teen wolf' – and we know how much fans love that trope.
Unfortunately, Wolfsbane has had a tumultuous time in Marvel Comics. Hopping from youngster to adult, you never quite know which version of the character you're getting. Hopefully, Josh Boone's The New Mutants realigns continuity and forces Marvel to reimagine the character as a young girl again. There's certainly enough space in the X-Men Universe for younger versions of characters. Not everything has to be Old Man Logan, you know.
12 ROY HARPER
When you think of the one DC character that's suffered more than anyone else, Roy Harper's name should be top of mind. The poor guy has been put through the wringer. From his substance problems to the constant losses in his life, it's remarkable that Roy is still able to stand up straight, never mind be a hero.
At the same time, it looks like the creative teams at DC have had a little too much fun treating Roy like Charlie Brown and pulling the ball away from him at the last moment. Ever since he stopped being the Green Arrow's sidekick, he's suffered blow after blow. Not cool!
When the New 52 debuted Cyborg as a full-fledged member of the Justice League, it marked a turning point for Vic Stone. He'd graduated from a Teen Titan to the premier team of DC – not many characters can claim that bragging right. He proved his worth on more than one occasion and even took over leadership of the group in a recent arc.
Unfortunately, the re-introduction of Martian Manhunter to the team has knocked him down the totem pole of importance. Right now, it seems like Vic could've been having more fun with his old buddies in the Titans than he is with the Justice League.
10 CLOAK AND DAGGER
The fact that the Cloak & Dagger TV series introduces the characters as teenagers tells you what you need to know about them. These two heroes are at their best when they're young'uns and navigating through the trials and tribulations of high school. The older they get, the less important they become in Marvel's stories.
Don't believe us? Well, tell us why Cloak and Dagger haven't become a part of the film universe then? They certainly have outstanding powers, but Marvel Studios would rather give Ant-Man two movies than focus on these two gems. It's a shame, really, as they're the human embodiment of the yin yang concept.
9 BARBARA GORDON
Even after the Joker injured Barbara Gordon, she remained in the picture as the invaluable Oracle. She might not have been Batgirl anymore, but she made sure that she used her brains and tech savvy to aid the cause. Since then, she's taken up the mantle of Batgirl again, but her importance to the Bat-Family has diminished.
You see, there are just too many Bats soaring around in Gotham City. You have Batman, Batwing, Batwoman, Signal, all the Robins, Cassandra Cain, Spoiler, and Batgirl. Things worked better when the Bat-Family was smaller and younger. We miss the days when it was just Batman, Robin, and Batgirl.
8 DICK GRAYSON
There's no doubt that we'll receive a lot of criticism for this entry. To be fair, Dick Grayson has achieved a lot since he went out on his own, becoming Nightwing, filling in for Batman several times, and even succeeding as a super spy. If you look at him now, as Ric Grayson, it's evident that no one knows what to do with him.
While fans debate over who is the best Robin, it's obvious that the answer is Dick, since he had the longest run with the Caped Crusader. Naturally, he had to grow up, but would anyone be upset to get a few blast from the past stories with him as Robin?
7 HARRY OSBORN
As we've seen Peter Parker develop into a young man, Harry Osborn has suffered more than any other character in the Spider-Man Universe. He played the role of Peter's best friend for many years and had his run as the Green Goblin. Now? Well, Harry's a bit part player in the storylines.
It's disappointing, really. While other characters such as Eddie Brock and Flash Thompson went on to become popular characters in Marvel, Harry fell to the wayside, acting more like a punchline from How I Met Your Mother. Sure, he might've found happiness as a father and husband, but any enthusiasm for him is non-existent nowadays.
6 JON KENT
It's obvious that DC will never leave the Superboy concept alone. We've seen several characters take up the mantle, and the latest one is Clark Kent and Lois Lane's son, Jon. Seeing Jon and Damian Wayne become the Super Sons has been a joy and we could do with more of those stories.
In a recent Superman arc, though, Jon reappeared as a much older Superboy. It's reminiscent of the way that all the kids in The Bold & the Beautiful suddenly get older one episode to the next. Whether this is a permanent change to Jon remains to be seen, but it looks like he lost out on his childhood here.
5 BOBBY DRAKE
To give credit to Marvel, it has tried to make some changes to Bobby Drake, in an attempt to reinvigorate him. After all, he's one of the original X-Men as Iceman, but he never achieved the same popularity as his peers. You could argue that Iceman's best moment was when he appeared in the Spider-Man and His Amazing Friends cartoon.
Sadly, he's also hopped from teenager to adult and back again more times than we can remember. Marvel can never decide which age it wants its mutants to be, and everyone suffers because of it. Unfortunately, Bobby is another casualty in the war of the constant reboots.
Fun fact: X-23 didn't make her debut in the comics; she appeared for the first time in Season 3 of X-Men: Evolution. Her creator, Craig Kyle, said she was his attempt to connect a Wolverine-esque character to the younger kids. While the Ol' Canucklehead has always been hot property in comics, Laura Kinney could become a new generation's favorite clawed mutant.
If you look at her reception in 2007's Logan, it worked. When X-23 is portrayed as a younger child, she ticks all the boxes and appeals to a wider audience. If she's aged and put in a Wolverine costume, she feels like a cheap knockoff of the grizzled X-Man.
If you want to imagine the ideal age for Raven, look no further than the Titans TV show. Teagan Croft's moody portrayal of the teenage Rachel Roth is pitch-perfect and works because teenagers are meant to be morose. Not only are her powers causing her emotional conflict, but she's also trying to navigate the path from childhood to adulthood, aka puberty.
Aging Raven, while keeping the same persona, just makes her look like a parody of goth girls. Additionally, it gets more difficult to play off the daddy issues she has with Trigon as she gets older. Perhaps with the next inevitable DC reboot, Raven will rejoin the Teen Titans as a teen.
Jubilee is very much a product of her time and embodies the early '90s culture. Even so, she found immense popularity among X-Men fans after appearing in the animated series and joining Generation X. She was part of the next breed of X-Men after the originals grew up.
The X-Men's varying timelines haven't done her any favors, though, and she's been all over the show. Sometimes she's the young Jubilee; other times she's grown up. At this rate, there's not one single person who can tell you which X-Men timeline is the correct one. Unfortunately, Jubilee is one of the characters who's suffered because of it.
Starfire is a peculiar character. When she was first introduced in New Teen Titans, her good looks and physique were heavily emphasized. (It was a different time and something like that wouldn't go down well in the modern era.) Since then, Koriand'r has fluctuated between being a teenager and adulthood in DC, depending on the requirement of the story.
In the long run, it's harmed her character. While she was undoubtedly the queen of the Titans and Dick Grayson's number one lady, she's lost in the shuffle of continuity now. She's neither here or there. While Anna Diop's version of the character thrives in Titans, the comic book Kori is in limbo.