Jason Todd was found by Batman breaking into the Batmobile as a kid. When Bruce saw potential in the young boy, he made him his second Robin. Jason was fueled by rage and revenge, which led to his painful death at the hands of the Joker, leaving Bruce distraught. After he was resurrected [because comics logic], he returned to Gotham as the masked vigilante Red Hood, where he takes an ultraviolent approach to dealing with Gotham’s criminals. Red Hood and the Dark Knight have butted heads ever since, debating on whose justice system is working for Gotham better.
If interested, read or watch the DC story arc: “Under the Red Hood”. It’s really good.
Taking a small break from the Robins to do some original content. It’ll be up in a couple of days.