According to Deadline, Brendan Fraser (Doom Patrol, No Sudden Move) has been cast in the upcoming Batgirl movie. Sources claim that Brendan will play the supervillain Firefly, however this is unconfirmed. Fraser will star alongside Leslie Grace (In The Heights), Jacob Scipio (Bad Boys For Life) and JK Simmons (Invincible, The Tomorrow War). 

You can read up on Batgirl in the Nightwing ongoing series and the upcoming Batgirls title (available 12/14/2021)