The Grundel is the only spirit from this series that also appears as an antagonist in Extreme Ghostbusters (1997).
This is the only episode in season three that was written by J. Michael Straczynski. Straczynski had refused to continue writing for the show to protest changes forced upon the show's creators by the network (the changes had been intended to appeal to a younger demographic). Due to the precipitous decline in the quality of the show during the season, the network asked Straczynski to write this episode and allowed him to adopt a darker and more serious tone than in other episodes in this season. Straczynski agreed to write the episode on the condition that he would not be asked to make changes to accommodate the character alterations the network had made.
Many alarmist parents complained about the Grundel, considering him to be an allegory for child molestation.
The Jabberwocky was a creation of Lewis Carroll. It first appeared in a poem of nonsense featured as a part of his novel "Through the Looking-Glass" and "What Alice Found There."
The Jabberwocky required four streams to contain, whereas the Grundel was contained with three streams.