Sludge

Sludge is a ghost from Jack the Reaper. It is one of the first ghosts encountered and is one of the weakest.

Appearance
Sludge is a large, purple, blob-like ghost. It is approximately 4 feet. It's covered in fat-like rolls, wrinkles, and warts. One of its biggest features is its single yellow eye with a black slit-shaped pupil. Its other big feature is its mouth, which is shaped like a vertical slit.

Locations
Sludge first appears in the Museum of Natural History. They later appear in the Engine Room of the Titanic and an alleyway in Times Square.

Jack the Reaper
Sludge is one of the first and easiest ghosts Jack encounters.

Death
As a human, Sludge was killed due to falling into a vat of an acidic substance. In death, Sludge has reanimated as a spirit made almost entirely of acidic ectoplasm.