Johnny Gabrielli was an orphan living on the streets of Suicide Slum with his friends Tommy Thompkins, Big Words and Scrapper. He was the most talkative member of the group, hence his nickname, and lived in a shack with the other members of the Newsboy Legion. They attempted to support themselves by selling newspapers, hence the name. When this failed in supporting the boys, they occasionally turned to petty crime. He and his friends were eventually taken under the guardianship of Officer Jim Harper, who was secretly the superhero the Guardian.
Johnny was created by Joe Simon and Jack Kirby.
When he grew up, he attended university, where he majored in science. After graduating from university he got work at Project Cadmus, as did the rest of the original Legion. He eventually got married, and had a son who resembled him almost identically, and who was later revealed to be an identical clone who had been created by Project Cadmus. Eventually he, his friends and the clones parted ways with Cadmus because of the changes being made to the project. He was killed alongside the members of the original Legion by Codename: Assassin.