Morpheus, a dream-demon, is making everyone in town have nightmares involving something that they are afraid of.
Eduardo loses his hair after Kylie rejects him.
In Egon's nightmare, he's walking naked through town, with everyone either laughing at him, whistling at him suggestively, or reacting in disgust, and when confronted by Morpheus about his nudity, rather then freak out, he says, "Hmm. Fascinating. I seem to be experiencing a neuro-soporific event ... with distinctly Freudian overtones." He's too analytical even for his dreams.
Eduardo's reaction to being told the consequences of crossing the streams in "Darkness at Noon."
"Keep it up, Garrett! You STINK!! PERIOD!!"
In "Fear Itself," we find out that Slimer's fear is a plate of vegetables. The sight of him screaming in terror when confronted with broccoli is hilarious.
In "Grease," Garrett attempts to set up a webpage for the Ghostbusters to drum up some business, only to be repeatedly blocked. Roland steps in and tries to get access to the Internet, but quickly grows frustrated himself.