Songbird is a Stable 63 experiment. And the bad news for the ponies that created her: she was a partial success.
A disgruntled being, she quickly finds life in a cage boring. So she decides to take control of her own life. Not only is that bad news for the ponies in Stable 63. It's also bad news for the entirety of the Wasteland.
Now, Songbird leads a danger-filled escapade of blood, torture, gore and sex.
And if anything about her is true, it's that Songbird is anything but a hero. She's not out to help, or to fix anything. She's out to do her own thing. And she's going to get it done, whatever it is.