The illustration depicts a group of four odd-looking ghosts.
Behind the scenes
Monster Ghosts was a piece of concept art for The Haunted Mansion.
It had a lasting influence on development of later incarnations of the Mansion: not only did it feature the debut of Gus (already more or less fully-formed) and of the Executioner (then only a Jailer, sans axe), but the skeletal hunchback on the forefront, given a cloak and hatbox, was eventually refashioned into the Hatbox Ghost, and not before appearing in this design in the Haunted Mansion maquette.
“Azalea“ (as the fans later nicknamed her) is the only character in Monster Ghosts not to have made it in any iteration of the ride or its spin-offs. Curiously crow-footed, the character seemed a throwback to Rolly Crump's work on The Museum of the Weird, almost a dwarved, uglier version of Crump's Mistress of Evil.