Most Information and Bio picture are from Xbox360Achievements.org and its posters xRogue 5x and Fizzmatix. Original thread can be found at this location.
Dredge is a Most Wanted Ghost in Ghostbusters: The Video Game. He is an emerald hued variant of the Black Slime Monster and can be confronted by capturing Olga the Terrible and completing ten Thieves jobs in any Library level. He appears in the Library levels.