The Batfamily is full of people who are capable of being terrifying, Batman is often times considered one of the scariest superheroes in DC and for a good reason, but one member of the Batfamily is even more frightening. Cassandra Cain, the second Batgirl, despite being a woman of few words is so scary she can even scare other members of the Batfamily.
Cassandra Cain was raised by the infamous assassin David Cain to become the perfect bodyguard for Ra's al Ghul. Cassandra was trained from an early age to be the perfect killer, she wasn't taught how to read, write, or even speak. The only language she knew was body language, the ability to read someone's intentions through their movement. This made her an incredibly dangerous fighter, but when she realized what killing truly was, she fled from her father. Despite all the darkness of her father, Cassandra still grew up to become one of the best heroes in DC, and one of the most terrifying. There's a reason Cass' version of Batgirl stars in more horrific covers. While Batman is certainly one of the most terrifying DC heroes to ever exist, after all, his entire mythology and reputation are based on criminals fearing him. But there's another member of the Batfamily who is so scary she's able to scare other members of the Batfamily. While Batman learned to be scary and to move unseen by training from various masters, such as Henri Ducard or Thaddeus Brown, Cassandra learned to be scary from an unlikely source.
In Batgirl (2000) #60 by Andersen Gabrych and Alé Garza, Cassandra mentions that she learned the monster unseen, that takes people down one by one while never spotted, is much more terrifying than the monster that is seen. She heavily implies she learned this from watching one of the most terrifying alien movies ever made. Given Cassandra's silent and stealthy approach, it's certainly easy to see why she'd be considered so frightening. Though she might not have the Xenomorphs' deadly tails or tongues, she's just as deadly.
Cassandra Cain's Stealth Makes Her Scary
This technique of never being spotted yet still taking down enemies one by one in order to build fear is the exact same that Batman employs at times, but Cassandra has one other thing that makes her version of it especially terrifying. Cassandra Cain is one of the most dangerous fighters on the planet, even Batman has stated if he were to seriously fight her it'd be unlikely that he'd win, she has defeated the likes of Shiva and an entire battalion of trained military soldiers, with her bare hands. Cassandra Cain is so terrifying Cass is even able to scare other members of the Batfamily.
Out of all the heroes in the Batfamily, Batman is often the one everyone thinks is the scariest, or maybe even Red Hood, but considering even Jason himself is scared of her, it seems the truly most terrifying member of the Batfamily is and always will be Cassandra Cain's Batgirl.