Egon and Ray reference species from the Cthulhu Mythos species: a Shuggoth, a Shambler, and a Ghast. They also mention Cthulhu Mythos writers H.P. Lovecraft and Clark Ashton Smith.
After Katarina kisses Slimer, he performs the Hopak.
The episode was recorded on May 16, 1990.
J. Michael Straczynski remembered having fun doing The Collect Call of Cthulhu (1987) and the great fan reaction. He decided to do a follow up episode set in Russia that featured the return of Cathulhu, the Necronomicon, and the Cult of Cathulhu.
During the trip, the Ghostbusters and Slimer fight over who gets to see the Aurora Borealis first.