Danny "The Weasel" Weaver is a character created by Batgirl writer Gail Simone, based of a nameless background character found in Alan Moore's Batman: The Killing Joke.
Major Story Arcs
The Killing Joke
Danny Weaver was one of the thugs Joker used the night he invaded the home of the Gordons, shooting and paralyzing Barbara Gordon. Danny and another thug would assault and abduct James Gordon for Joker's plans to mentally break him, in an effort to taunt Batman.
In the post-The New 52 continuity, it has been three years since the events of the Killing Joke, and thank's to an experimental surgery, Barbara Gordon has regained her mobility, and started fighting crime as Batgirl once again. Her return to crime fighting is riddled with second guesses and hesitation due to her traumatic past, but she attempts to leave her past behind in order to effectively act as Batgirl again. One night when Barbara was in pursuit of a new rouge by the name of Grotesque, she follows him and his men into the sewer where Grotesque uses his metahuman abilities to escape. She searches through Grotesque's knocked out henchmen to find Weaver once again, bringing back many bad memories. She becomes so emotional that she ends up letting Weaver go before she allows herself to do anything she would regret.