She wasn't the only original character on the team, but was much more popular than Spyke, Storm's nephew who was essentially a male Marrow who even joined the Morlocks at one point. However, he did inspire two similar characters. A modified version of Spyke named "the Spike" was a member of the Milligan-Allred version of X-Force, but he fell prey to the team's infamously high mortality rate. More recently, a canon nephew for Storm named David Munroe was introduced, though it has not yet been revealed if he is a mutant.
The mutant superhero Firestar was created for Spider-Man and His Amazing Friends (issues with the rights to Fantastic Four characters scuttled the original plans for the Human Torch, who's canonically a long-time friend of Spidey) and, like Spidey's other amazing friend Iceman, was supposed to be a former member of the X-Men. She was imported into the Marvel Universe in X-Men #193, had her own limited series, and later served as a member of the New Warriors and The Avengers.
Also the Ultimate version of Firestar has joined the X-Men, followed only recently by the 616 (main universe) version, so the circle is complete.
Harley Keener, the Tagalong Kid from Iron Man 3, made his first mainstream appearance in the WEB of Spider-Man comic as one of several kids working under Spidey in the W.E.B. team.
In The Fantastic Four (1978), the Human Torch was replaced by a Robot Buddy named "H.E.R.B.I.E.", not (as one rumour stated) because the producers were afraid children would immolate themselves trying to imitate the Torch, but because there was a solo Human Torch movie deal in the works at the time. Assorted versions of HERBIE have since appeared in the comics as an example of the sort of random stuff Reed Richards invents between adventures. (In the most recent cartoon, "Herbie" is the name of Reed's computer, a capacity he appeared in in Fantastic Four: World's Greatest Heroes first, being the Baxter Building's AI similar to JARVIS in the Iron Man movies.
Herbie is currently Franklin Richards' robot guardian, at least in the Franklin Richards one-shots and Power Pack minis.
HERBIE's been depicted pretty regularly lately as a model of robot that Reed produced dozens of to perform various odd jobs around the Baxter Building.
In the alternate future of the Marvel Comics 2 universe, Reed has seemingly transplanted his brain into a HERBIE robot. He's actually operating it remotely from the Negative Zone.
In X-Statix, Latin Lover El Guapo was a character added to the In-Universe X-Statix movie to help it appeal to a broader audience (there aren't many traditionally attractive men on the team), and to hold the Conflict Ball by, in being so handsome, disrupting the other characters' relationships. However, the actor playing him is an actual mutant who eventually is asked to join the team for real as El Guapo. He proceeds to do the exact things movie El Guapo was created for, completely on accident.
X-Men: The Animated Series gave an interesting example in Morph. He was based on a comics character, Changeling, who had been killed in the 1960s, and was Killed Off for Real in the pilot as a Sacrificial Lion. He proved so popular in his brief screentime that not only was he brought back to life in the cartoon, but an alternate-reality version of Changeling going by the codename Morph was introduced as a major character in the comic crossover event Age of Apocalypse. Another AU version of Morph later became a main character in Exiles.
Reptil, originally a character created just for The Super Hero Squad Show toyline (which came before the show, remember), was introduced in the comics in an Initiative special in early 2009. He then became a student at Avengers Academy the following year, just barely getting a main character spot in a book before the TV show debuted. As a Hispanic character, he filled a demographic need, and, as a Fun PersonifiedAscended Fanboy who can transform into dinosaurs, brought something unique to the table.
The Next Avengers debuted in a direct-to-DVD animated film before appearing in the first arc of Brian Bendis' Heroic Age relaunch of the main Avengers book a few years later. They later showed up in Avengers World (a companion book to Jonathan Hickman's Avengers run) as well.
In a manner similar to Aqualad and Reptil, the new Nova, Sam Alexander, was created for the Ultimate Spider-Man (2012) animated series and was introduced into the comics during the Avengers vs. X-Men crossover event. His animated teammate, White Tiger (aka Ava Ayala) was created for the comics, but Marvel liked the idea of the character so much that they immediately worked her into the cartoon, before her first appearance had even been published.
The Anton Vanko version of Whiplash was introduced in the comics in order to have a version of the character similar to the unique take on Whiplash seen in Iron Man 2.
Sophie "Chat" Sandoval, a mutant who Speaks Fluent Animal, first appeared in Marvel AdventuresSpider-Man as a friend of the teenaged Emma Frost, and later the teenaged Peter Parker's girlfriend. A couple of years later, she was introduced to mainstream Marvel in Spider Girl 2011 (the Anya series) #4.
J.A.R.V.I.S., the AI that replaces Edwin Jarvis in the Iron Man films, has since appeared in the comics as the internal computer of Pepper's armor. Apparently, the comics version's personality is modeled on the human Jarvis.
Iron Man 3030 (a.k.a. Rhodey Stark) from Jonathan Hickman's Avengers also used a version of J.A.R.V.I.S. as her suit's A.I. system.
Arno Stark was originally introduced as Iron Man 2020, Tony Stark's descendant from an alternate future. Kieron Gillen brought Arno into the official Earth-616 canon as Tony's long-lost older brother in ''Iron Man 2012. He eventually became Iron Man in comics published in the year 2020.
Raza was originally created for the first Iron Man movie as a Race LiftedExpy of Wong-Chu from the comics. In the 2010 Invincible Iron Man Annual, the Mandarin, while talking about his past, also talks about Iron Man's origin, and mentions Raza being there. The Ten Rings, the terrorist organization Raza worked for, officially became canon in Ironheart #1.
The Age of Apocalypse saw three straight examples: Abyss, who is a hero in the classic Marvel Universe; Emma Stead, a member of the Hellfire Club's London branch, whose AoA counterpart was Damask; and Genocide, whose counterpart is Holocaust. There were also the Bedlam Brothers, Jesse and Christopher Aaronson, whose Earth-616 counterparts would later show up in X-Force. Additionally, Dark Beast and Sugar Man made the jump to the Earth-616 following the end of the event, with Dark Beast becoming Beast's Evil Counterpart.
When the original Guardians of the Galaxy went back in time, Vance Astro talked his younger self out of joining the Air Force and caused the premature emergence of the latter's telekinesis, causing his universe to become an alternate timeline. The mainline Marvel Universe version of Vance Astro is the New Warriors / Avengers member known as Justice.
Spider-Verse basically canonized every single adaptation of Spider-Man ever created, officially incorporating them into the Marvel Multiverse in the process. Yes, this includes stuff like the Hostess snack cake ads, the newspaper comic strip and the ill-fated musical.
Sequel storyline Spider-Geddon also featured the Spider-Man from the PS4 game in a key role.
Though he is never named as such, a villain clearly based on the Fifth Avenue Phantom from Spider-Man (1967) once tangled with Spider-Girl.
Melinda May, Leo Fitz, and Jemma Simmons originated in Agents of S.H.I.E.L.D. before being made canon in the comics.
Grant Ward gets added later on too. Unlike his TV counterpart, he is introduced as a villain from the outset, since his addition didn't happen until over two years after the airing of the TV episode that revealed he'd been Evil All Along, meaning everyone who cared presumably already knew.
Essentially all the leading original characters from Agents of SHIELD have made it into the comics, except for Skye who turned out to be the MCU version of Daisy Johnson.
Jiaying also made the jump in one of the S.H.I.E.L.D. 50th Anniversary one-shots, while Gordon (the eyeless Inhuman) appeared in the Uncanny Inhumans series.
Marvel worked with video game company Kabam to develop Guillotine, a heroine from France. The character was added as one of the playable fighters in Marvel: Contest of Champions shortly after debuting in the comics.
Red Widow was created for the prose novel Black Widow: Forever Red before migrating over to the comics. Like the Batgirl and Aqualad examples, she actually appeared in the comics a few months before the novel was in stores.
Jason Stryker, William Stryker's son from X2: X-Men United, was brought into the official Marvel canon in All-New X-Men. However, unlike his movie counterpart, this version of Jason is a militant Boomerang Bigot.
Yondu basically got the Nick Fury treatment. In the comics, Yondu is a Noble Savage archer from the 31st century, but in the movie, he's a country fried redneck space pirate from the present day, and doesn't use a bow. The comics compromised by introducing a movie-inspired version of Yondu as the distant ancestor of the original alongside his gang of Ravager Space Pirates.
Erik Selvig from the Thor movies made the jump to the comics as a S.H.I.E.L.D. scientist. Darcy Lewis, Jane's friend from the films, would later make her canon debut in the 2022 Scarlet Witch series.
Hope Van Dyne/Pym is another example similar to the Nick Fury one. Hope is an existing character, but only from the MC2 continuity, where she's actually a villain called the Red Queen. The Ant-Man movie used an In Name Only version of Hope as a hero and set her up to become the MCU version of The Wasp, so the comics responded by bringing in an alternate version of Hope as The Unstoppable Wasp. Her name was changed to "Nadia", which is Russian for "Hope", though Mark Waid claims the name thing is a coincidence.
Likewise, Luis from the Ant-Man movies briefly shows up in Astonishing Ant-Man as Scott Lang's cellmate in Miami.
Sokovia from Avengers: Age of Ultron is an example of an entire country being canonized in the comics, making its debut in the seventh issue of Captain America: Steve Rogers as a former Soviet Bloc dictatorship led by General Kamil Novoty.
Daredevil: The Kingpin mini-series also saw the comic debut of Mitchell Ellison, a character previously created for the Netflix show as a replacement for J. Jonah Jameson.
Similar to the Yondu, Nick Fury and Hope Pym examples, Exiles introduced an alternate universe version of Valkyrie who is explicitly modeled after Tessa Thompson's portrayal of the character in Thor: Ragnarok. The series also incorporated the alternate universe Peggy Carter version of Captain America from Marvel Puzzle Quest.
King in Black introduced another new Valkyrie based on Thompson's version of the character, this time in the main continuity. Her name was later revealed to be Runa.
In yet another example, the 2018 relaunch of Black Panther introduces parallel versions of Nakia and M'Baku who are modeled after their more heroic counterparts from the movie.
Investigative journalist Jackie McGee is an adaptation of Jack McGee from the Incredible Hulk live-action show, changed from a white man to a blackwoman.
The same run also introduced another character from the TV series: Dell Frye, the violent and power hungry man who had actually become a Hulk-like creature before Banner, albeit as a man who was presumed dead as a teenager and appearing like a corpse. His assistant, Jeffery Clive also appeared, albeit as a Mad Scientist working for the government unconnected to Frye.
Related to Hulk, but introduced decades before Ewing's run: Hulk's father originally debuted in the TV series (episode "Homecoming", 1979), having his first appearance in the comics three years later (1982). His name was changed from DW Banner to Brian Banner. His morality was also changed.
The Agents of Atlas series also featured a cameo from Adi (given the codename "Codec") from the Japanese Marvel Future Avengers anime series, before he and the rest of the Future Avengers were given their own backup stories in the Future Fight Firsts series of one-shots (which mainly showcase White Fox, Luna Snow, and Crescent).
The Unbelievable Gwenpool: Gwenpool originated as part of a series of gimmick covers depicting Gwen Stacy dressed as various other Marvel characters. The cover featuring her in a pink and white Deadpool costume proved popular enough that Marvel brought the design into their universe as an actual character.
In Immortal Iron Fist, the Prince of Orphans is a 1940s Centaur Comics character — John Aman, the Amazing-Man — who had fallen into the Public Domain. Part of why he was introduced was that Iron Fist's 1970s origin was partially inspired by John Aman's origin.
While as of July 2021, it's yet to see the light of day, the planned miniseries Punisher vs. Barracuda was meant to see the Earth-616 debut of the titular Barracuda, a villain from The Punisher MAX.
Rikki Barnes from Heroes Reborn had literally migrated to the main Marvel Universe as of Onslaught Reborn. As of the 2019 series about her time as Nomad, her brother John got an actual counterpart on Earth-616, only presumably without being the grandson of Bucky Barnes and Peggy Carter.
Jodie, Lou, and Melissa from M.O.D.O.K. (2021) have entered the Earth-616 canon as of the M.O.D.O.K.: Head Games miniseries, starting off as M.O.D.O.K.'s hallucinatory family before being brought to life with Super Adaptoid bodies.
Venompool, an alternate universe version of Deadpool from the Marvel: Contest of Champions video game, was brought into the Marvel Universe in Rob Liefeld's X-Force: Killshot special. Similar to the Valkyrie example listed above, the issue also features an alternate universe version of Domino based on Zazie Beetz's portrayal of the character from Deadpool 2.
The 2021 Shang-Chi series by Gene Luen Yang introduces Li, the titular character’s mother from the movie, into the Marvel canon. Her prior absence is explained as her having been trapped in the Negative Zone for many years after defying her villainous husband.
Captain Carter made the jump to the comics following What If's first season, eventually having her own solo title Captain Carter.
Moon Knight (2021) #25 and the Moon Knight City Of The Dead limited series see the comic debut of Layla El-Faouly/Scarlet Scarab from the Moon Knight (2022) TV series (Moon Knight #25 is Layla's debut, featuring her past with Marc as members of a mercenary team, and City of the Dead is her debut as Scarlet Scarab).
Ka-Zar: Ka-Zar actually started as a standalone pulp magazine character (which was also run by Martin Goodman, the head of Timely Comics) which predates this comic series by three years. The first five comic stories with Ka-Zar are directly adapted into comic form from that magazine.
Dan Slott’s Silver Surfer run saw an appearance from the Ding-A-Ling Family, a clan of criminal space hillbillies who were created for a Hostess Twinkies ad featuring Thor way back in The '70s.
Similar to the Gwenpool example, Marvel ran a special variant cover program in 2023 dubbed New Champions, each of which showed the hypothetical Kid Sidekick of an existing Marvel hero. Peach Momoko's contribution was Maystorm, a mutant girl from Japan who was intended to be Storm's teenage protégé. While most of the other teen heroes remained confined to their respective covers, Momoko later brought Maystorm into the comics as one of the main characters of the post-Ultimate Invasion relaunch of Ultimate X-Men (2024).
appeared in one issue of Spider-Man Family, which was a long Mythology Gag to the show.