Trivia
Phantomaniacs/Fear and Laughter in Burbank/Bride of Pinky/Things That Go Bump in the Night
Animaniacs
When Brain explains to "Pigor" (aka Pinky) that he hires only the top masons for building his castle he emphasizes those only schooled in the latest techniques of "Wall Stone Craft"; this is a pun to Wollstonecraft, the name of Frankenstein's author, Mary Wollstonecraft Shelley.
Dot tells Nicklewise that he should stop eating so much dairy. "It" takes place in the fictional town of Derry, Maine.
The Warners are dressed as the Marx Brothers for Halloween (which makes sense, as Yakko generally channels Groucho anyway).