The Doom Ghosts are multi-eyed and multi-armed ghosts from another dimension.
While working on the Interspatial Teleportation Unit, Ray Stantz generated a portal to another dimension populated with the Doom Ghosts. Ron Alexander put his head through the portal and met the ghosts. At least eight of them were present and yelled "Doom!" at Ron. Ron was not impressed.
While the Ghostbusters were preoccupied with finding and recapturing the ghosts missing from their Containment Unit, a P.K.E. spike near the George Washington Bridge went unnoticed. A Doom Ghost manifested and enveloped the area in a purple fog. The bridge was closed and the FBI notified Special Agent Melanie Ortiz. She borrowed Winston Zeddemore, Jillian Holtzmann, Rookie, Dani Shpak, and Lou Kamaka for the case. They arrived at Fort Washington Park and picked up two readings. Holtzmann suggested splitting up and chose Lou and Dani for her team. Melanie, Rookie, and Winston started a sweep south of the Lighthouse. Holtzmann was the first to sight the ghost and fired but it receded and the Proton Stream passed harmlessly through a hole in the fog. Lou and Dani found Holtzmann but the ghost formed tentacles and held them in midair. Holtzmann attacked it with the Proton Glove but it vanished again. Dani checked the 80-C Dimension's P.K.E. Meter and was confused. It said the ghost was the still present. It whacked them with a tentacle soon after. Melanie, Rookie, and Winston provided cover fire but the ghost vanished again. Holtzmann realized the fog was the ghost and broke into the Lighthouse. She activated the searchlight and fog horn. Holtzmann's theory was correct and the ghost revealed its true form after its senses were rattled. They soon trapped it.
- On page 8 of Ghostbusters Crossing Over Issue #3, Melanie mentions author Stephen King and Maine, alluding to "The Mist" in response to the ghost's fog.
- On page 10 of Crossing Over #3, the ghost's fog form is visually based on Belleranthon from The Real Ghostbusters episode "The Thing in Mrs. Faversham's Attic".
- Special Agent Melanie Ortiz (2018). IDW Comics- "Ghostbusters Crossing Over Issue #3" (2018) (Comic p.8). Special Agent Melanie Ortiz says: "Fort Washington Park has had a lot of spectral activity, usually not enough to warrant investigation.. but a big PKE spoke registered and then this fog rolled in."
- Jillian Holtzmann (2018). IDW Comics- "Ghostbusters Crossing Over Issue #3" (2018) (Comic p.13). Jillian Holtzmann says: "Oh, it's barely a Class 5."