The Ghost Priests are a collective of ghosts of priests from various eras in time.
During a bust at the United Nations Building, the Ghostbusters were unexpectedly surrounded by a multitude of Ghost Priests in the assembly room. They did not attack the Ghostbusters nor aid the Werecat Ghost and only screamed "No!" Egon Spengler checked his P.K.E. Meter and determined they were not subservient manifestations and were wholly separate from the Werecat. After it was trapped, the Ghostbusters were about to turn their attention to the Ghost Priests but they vanished.
The Ghost Priests and Gottskalk Nikulausson manifested in the latter's hidden tomb near Holar, Iceland when the Ghostbusters entered. They continued to shout "No!" at them. After Winston Zeddemore recovered the Rauoskinna, the Ghost Priests surrounded him and kicked at him. Winston opened his Trap and captured all of the ghosts at once. Since the Trap was not designed for that much psychokinetic energy, the Ghostbusters fled the tomb. Gottskalk and the priests emerged from the tomb as one gigantic amalgamation. Still tethered to the Rauoskinna, it followed the Ghostbusters until Peter Venkman sprayed the book with positively charged Psychomagnotheric Slime and Egon Spengler/Animated threw a Proton Grenade at it.
- Peter Venkman refers to the clergy ghosts as the Sarducci Choir, a nod to the fictional character Father Sarducci. 
- Some of the ghosts appear to based on fictional priests from horror movies
- On page 6, panel 2, the ghost between Winston and Ray appears to be visually based on Father Brennan from "The Omen"
- On page 6, panel 3 the ghost in the middle appears to be visually based on Kane from "Poltergeist 2"
- On page 8, panel 4 two of the ghosts appear to be visually based on Donald Pleasance as the priest from "Prince of Darkness" and Father Damien Karras from "The Exorcist"
- On page 2 of Ghostbusters International #10, Peter's critique of their 'tune' is a callback to Issue #1 when he referred to them as Sarducci's choir.
- Ongoing Series
- Egon Spengler/Animated (2016). IDW Comics- "Ghostbusters International #10" (2016) (Comic p.8). Egon says: "That high-spectrum Class 5 out there is tethered to this book, meaning we're dragging it along with us."
- Peter Venkman (2016). IDW Comics- "Ghostbusters International #1" (2016) (Comic p.8). Peter says: "And someone tell the Sarducci Choir to can it, huh?"
- What Came Before! (2016). IDW Comics- "Ghostbusters International #4" (2016) (Comic What Came Before!). Line reads: "Peter, Winston, and Ray were dropped off on Poveglia Island, where they tracked down a Plague Doctor apparition, who, like the Venetian Shop Ghost in Ghostbusters International #2 and the Ghost Priests in Ghostbusters International #1 seemed eager to nudge the Ghostbusters away from this particular investigation."