Banshee is a screaming old ghost who steals people's youth and is the antithesis of her sister Syren. While not explained, she isn't the only Banshee as The Real Ghostbusters had a banshee to deal with which makes it one of a kind of creatures. She later ended up trapped with her sister and put in the Containment Unit. edit Personality
She was a mean older looking woman, that was nasty and careless about anyone other than her sister.