This is Rachel's second speaking appearance and first main appearance.
This episode reveals that Rachel lives just a few houses away on the same street as either Howard or Randy.
In the background of the "scare-age," a plastic figure snowman is wearing a hockey mask similar to that of Jason Voorhees from the "Friday the 13th" franchise.
The Forbidden Knowledge of the Shadow Warrior in the NinjaNomicon reappears, having previously appeared in "Dawn of the Driscoll."
The emblem of the Norisu Nine appears on the Temple of the Forbidden Knowledge of the Shadow Warrior. This implies some kind of connection between the Norisu Nine and the Shadow Warrior; he could have been one of their main enemies or possibly even one of them.
Howard's line, "Childer-en of the night!" references the famous line from Bram Stoker's 1897 novel Dracula (and its many film versions), "Listen to them, the children of the night. What music they make!" (There the "children of the night" are wolves.)
Rachel's line, "The power of cute compels you!" is a parody of the line "The power of Christ compels you!" from the 1973 horror film, The Exorcist, drawn from the Roman Catholic rite of exorcism.
The Halloweenja's magic circle may be a reference to the Disney cartoon Gravity Falls, though necromantic circles are commonplace in stories of witchcraft and the supernatural.
The part where Randy throws the NinjaNomicon and sucks the Halloweenja suit into it is reminiscent of how the "ghost traps" are used in the 1984 film Ghostbusters.
It's revealed in this episode that McFist is creeped out by retro Halloween music.
The last line of "The Ghost Boogie" sung over the credits is "I ain't 'fraid of no boogie," a parody of the line from the song "Ghostbusters," "I ain't 'fraid of no ghost!"