Impulse (DC Comics)

Richard Kent Shakespeare was revealed to have used the codename in a flashback sequence in Legion of Super-Heroes vol. 4 #53.[1][2]

Suffering from a hyper-accelerated metabolism, Bart Allen was aging at a faster rate than that of any human being thus causing him to appear the physical age of twelve when he was chronologically, and mentally only two years old. To prevent him from developing mental health problems, he was raised in a virtual reality machine which created a simulated world that kept pace with his own scale of time. When it became clear that this method was not helping, his grandmother, Iris Allen, took him back in time to the present where The Flash, Wally West, tricked Bart into a race around the world. By forcing Bart into an extreme burst of speed, Wally managed to shock his hyper-metabolism back to normal.[3] Because he had spent the majority of his childhood in a simulated world, Bart had no concept of danger and was prone to leaping before he looked. The youth proved to be more trouble than Wally could handle, and he was pawned off onto retired superhero speedster Max Mercury, who moved Bart to Manchester, Alabama. In Impulse #50, it was revealed that Batman actually named Bart "Impulse" as a warning, not a compliment.

Iris West discovered that she and her brother were sharing access to the Speed Force, and decided to end that symbiotic relationship, taking all the power into herself. Jesse Chambers, guided by the late Johnny Quick, uses her Speed formula to save Iris' life. Iris embraces her new role, choosing to take up the mantle of Impulse, which Bart used before he joined the Teen Titans as Kid Flash.[4]

• In the original Kids' WB pitch for the Justice League animated series, Robin, Impulse, and a teenage female version of Cyborg were to be seen as junior members of the League. It was later decided to avoid their introduction, so as to avoid making Justice League seem like the old Super Friends series. The corresponding short animation is available as a bonus on the season one DVD of Justice League.[5]
• Bart Allen appears as Kid Flash in an episode of Mad, voiced by Jason Marsden. He joins the other superheroes in a musical number that asks Superman, Batman, and Wonder Woman about being called "Super Friends." His part involved telling them that they would prove their worth if they sit through Twilight with him.
• Jason Marsden reprises his role as Bart Allen in the Young Justice episode "Bloodlines". He is first seen in the year 2056 working on a time machine and being wished a farewell from an unknown person in a Belle Reve jumpsuit. He then travels back to the year 2016 and is transported inside Mount Justice where he is confronted by Nightwing, Robin, and Beast Boy. After trying to escape, he is stopped by Nightwing. He tells the three heroes that he is the grandson of Barry Allen and Iris West Allen and that he is a time-traveling tourist, but they could call him Impulse. To prove that he is from the future, he reveals the secret identities of all three heroes. Impulse then escapes and heads to Central City to meet his family. When he meets his grandparents, he inadvertently reveals that his grandmother is pregnant with twins, a boy and a girl, and also meets the retired Flash, Jay Garrick, and the retired Kid Flash, Wally West (who is Allen's first cousin once removed). The reunion is cut short when a villain calling himself Neutron attacks Central City. Impulse joins his grandfather and cousin in fighting the villain. During the battle, it is revealed that he's actually faster than Kid Flash and close to Flash's speed. When it seems that Neutron is going to overload and explode for a second time, Flash attempts to take him to the desert. This attempt fails when Impulse joins him and seems to accidentally trip the both of them. Neutron explodes again, but the two are saved by Kid Flash and Jay Garrick. Impulse then returns to the regenerating Neutron and throws an unknown device at him, which turns him into an ordinary human. When the other heroes ask him what happened, Impulse claims he has no idea how Neutron became human again. Later on back at the Mount Justice, Nightwing confirms through a DNA test that Impulse is who he claims to be. Impulse then enters his time machine intending to return to the future, but the machine was damaged and he claims that he has no idea how to fix it. The episode ends showing a flashback to 2056, just before Allen leaves for the past. The unknown person is revealed to be an older Neutron, who gives Allen the device that can cure him and informs him that he will not be able to return to the future. The flashback also reveals that Allen is going back to the past to save his grandfather's life and save the future. After he leaves Neutron is altered out of his jumpsuit into regular clothes, only to realize that nothing else changed. In the episode "Before the Dawn", it is revealed that his main reason for coming to the past was to stop Blue Beetle from becoming evil and causing a Reach apocalypse. In the second-season finale, "Endgame," Bart becomes the new Kid Flash after the apparent "death" of Wally West.

• An episode of Smallville entitled "Run" featured a speedster named Bart Allen, portrayed by Kyle Gallner. Bart also carried around identification with the names "Jay Garrick", "Barry Allen", and "Wally West", the first three Flashes in the main DC Universe. He was portrayed as a self-centered teenager who used his powers as a thief for personal gain, although he showed signs of changing his ways by the end of the episode when he helped Clark save his father. As a sort of in-joke, he flirted with Chloe Sullivan and told her that he is from 100 years in the future (he jokingly claimed that they were still in love by that point). At the end of the episode, after Bart said that he will travel the world to find others like him and Clark, maybe starting "a club or a league or something", Clark and Bart had a race; just as Clark seemed to be catching up to him, Bart turned and gave him a slight wave and disappeared into the distance. Gallner reprised his role in the season six episode "Justice", using the codename Impulse and wearing a costume of sorts for the first time on air. He appeared as part of a team led by Green Arrow. According to Green Arrow, he found Bart one night in Star City during one of his patrols and saw that he was about to help himself to a "free meal", but, seeing goodness in Bart, he helped give him "direction". Along with Aquaman and Cyborg, they formed a team to stop Lex Luthor and his LuthorCorp 33.1 project, the group rescuing Bart from a lab after he was captured. During missions, he was called "Impulse," a name he did not choose himself, much like in the comics. He was composed as more of a fusion of various Flash traits and personalities. When Clark and Lex disappeared from the arctic in the Fortress of Solitude, Bart and Victor Stone searched the entire southern hemisphere for them and found nothing. Later, Oliver mentioned that Clark went on a JL mission with Bart in Keystone City and he was seen along with AC, Victor, and Dinah on Chloe's computer screens in the Isis Foundation. Kyle Gallner returned once again in the season 8 finale "Doomsday" to help Clark fight his biggest enemy yet. However, he eventually turned his back on Clark in order to save him. He was last seen at Jimmy Olsen's funeral, and Chloe later mentioned to Clark that Bart, along with teammates Oliver and Dinah, disappeared from the face of the Earth and that she feared the worst. Bart's name is mentioned in the season 9 episode "Escape" when Clark tells Chloe that Bart is in town for the weekend. Impulse gets later mentioned (by codename) in the season 9 episode "Checkmate" by Amanda Waller, demanding to know everyone who had ever worked with Watchtower (a.k.a. Clark and Chloe).[6] In the season 10 episode "Icarus", Impulse attends Carter Hall's funeral but his face is not shown. In the Season 11 comic book continuation of the television series, Bart sacrifices his life, sending the Black Flash into the Speed Force, along with himself. However, Clark later meets a mother and a child when he time travels to the 30th century, and the latter's name is revealed to be "Bartholomew Allen" and he bears a resemblance to his namesake, suggesting a possibility that the boy is either Bart himself (ironically making his claim to Chloe true) or Bart's descendant, the latter giving Clark hope that he is still alive but trapped in the speed force.
• In the Arrow/Flash crossover episode "The Brave and the Bold", Captain Quentin Lance mistakenly calls Barry Allen "Bart Allen", though Barry later corrects Quentin; his first name is actually Bartholomew. John Wesley Shipp revealed that there are talks about having Bart Allen on The Flash.[7] In The Flash episode "Cause and Effect", Barry's memory is accidentally erased in a S.T.A.R. Labs mishap. When he learns his name is Bartholomew Henry Allen from his driver license, the amnesiac Barry insists on being called "Bart", as that name "feels more natural" to him. Once his memories return, he resumes being called Barry.

In Injustice: Gods Among Us, Bart Allen's name is listed on a hit list during Deathstroke's outro.