Jason Todd is a vigilante superhero with multiple names. Originally he was the second Robin, Batman's sidekick after Dick Grayson grew too old. During A Death in the Family he was murdered by the Joker, although he would be resurrected many years later during Under the Hood and become the anti-hero Red Hood. His successor as Robin was Tim Drake. His violent attitude towards criminals has made him a controversial figure, crossing moral lines to pursue his ends even as a teenager, and repeatedly demonstrating his willingness to kill as an adult. His death motivated Batman for many years and his costume was held on display in the Batcave, although since his return they have mainly been opponents. He has been a member of the Batman Family, the Teen Titans and the Challengers from Beyond. Jason Todd was created by Gerry Conway and Don Newton, first appearing in Batman #357. (1983)
A mysterious character from the Teen Titans animated show, Red X was originally an alternate identity for Robin, but someone later stole the name & costume. Red X's motives are usually selfish & unknown. He made a comic book appearance in the show's comic spin-off, Teen Titans Go! Red X uses a variety of skill and gadgets to defeat anyone who stands in his way; presumably Jason Todd.
Talon is the Earth-3 counterpart of Robin and sidekick of Owlman, an evil counterpart of Batman. He was once a villain but has since changed his ways and traveled to New Earth with his girlfriend Deula Dent, joining the Teen Titans for a period.
5.) Red Hood
Jason's new origin is revealed in a special zero issue, which changes the manner in which Batman first met Todd (stealing medicine from Leslie Thompkins, after she had treated him from a brutal beating). The back-up introduces a massive retcon in which the Joker is responsible for orchestrating the major moments of Todd's life such as his father's imprisonment and death, his mother's overdose, his introduction to Thompkins and his adoption of the Robin identity. Considering the Joker is the one narrating this segment, it is open to debate whether he is telling the truth or not. Though only lightly touched on, his resurrection is also simplified: he is resurrected after he is placed into the Lazarus Pit by Talia al Ghul.
In the aftermath of the apparent death of Batman, Gotham City becomes the site of a three-way war as Two-Face, The Penguin, and Black Mask struggle for dominance. With the Gotham City Police Department crumbling under the pressure, the Bat Family calls in help, all the while struggling to determine the answer to the big question: who will assume the mantle of the Bat?
7.) Arkham Knight
Jason Peter Todd was once Robin, working alongside Batman. He was tortured and believed to be killed by the Joker, however it was discovered that he was alive and hell-bent on destroying his former mentor as the Arkham Knight before becoming the Red Hood to assist Batman once again after laying his vendetta to rest. As the Arkham Knight, he works with both Scarecrow and Deathstroke to turn Gotham into a city of fear.