Talia al Ghul is the tetartagonist of the 2014 DC Animated Universe film Son of Batman, a background character in it's 2015 sequel Batman vs Robin, and later returned as the true primary antagonist of the 2016 film Batman: Bad Blood.
She is the leader of the League of Assassins.
One night, years ago, Talia spent the night with Bruce Wayne and tricked him into being with her, which lead to her being pregnant with their son, Damian. Talia kept the child a secret from Batman and raised Damian in the ways of the League of Assassins.
When Damian was older, Talia, Damian, and Ra's were overseeing the training of the League until they were breached by a League of Assassins led by Ra's al Ghul's former henchman, Deathstroke. Talia led the defense of the League's base, then after the death of Ra's, brought her son to Batman for safety.
Deathstoke was eventually defeated and Talia departed to rebuild the League, leaving Damian with Batman.
However, after this, Talia has abandoned her morality and relinquished her compassion for both Damian and Bruce, seeing both primarily as tools to serve her purpose. Talia plots to use Bruce to use the new communication software of Wayne Enterprise to brainwash the various political leaders of the world. She recruits various villains to serve as her henchmen. Her efforts are ultimately thwarted by the "Bat-Family" and Talia is furious that she failed at both ambitions of controlling the world and having Bruce at her side, Talia retreats. She proceeds to escape on her jet, but is confronted inside by Onyx and counterattacks causing the jet to crash and leaving their fates unknown.