An artifact left behind by Norlock traps the three teams in their worst nightmares, forcing Gaz and Nyx to enter their dreams to save them.
- All Therapists Are Muggles: Lampshaded when Viera notes how Team Save Earth probably need to see a therapist after all the things they've dealt with, only for Dib to bitterly point out how, given the sort of stuff they deal with, said therapist would just have them shipped off to the crazy house.
- But for Me, It Was Tuesday: The narration notes that the Catastrophe causing chaos is just another day in Doomsville, and it's apparently not even the craziest thing that the heroes have dealt with that week.
- Continuity Nod:
- When dealing with the Catastrophe, Dib mentions the time that Zim turned a class hamster into a kaiju.
- Zim's past association with Norlock is what kickstarts this chapter's plot.
- This isn't the first time that Skoodge has been shown having nightmares about the Slaughtering Rat People.
- The courtroom that the Meekrob drag Tenn into in her nightmare is the same one she viewed back in "Tenn's Mission of Doom".
- Gaz and Nyx use the Dream Walker spell that Dib used several times in Season 1.
- Gaz's nightmare ties into trauma from her time as "Pig Girl".
- Dead Man's Switch: How Norlock describes the seal on the Nightmare Weaver's containment urn, which only he could reset and which had a spell on it to compel the Weaver to go after anyone who was near him at the time of his death.
- Dream Episode: The entire chapter is built around the characters' nightmares.
- Enemy Mine: Since the Nightmare Weaver's Mental World can only be escaped if everyone it's trapped is broken free of their nightmares, the three teams reluctantly work together to fight it.
- Hoist by His Own Petard: Once they break each of its victims out of their initial nightmares, the Nightmare Weaver drags them all before it and manifests their fears again after displaying a recorded message from Norlock. Unfortunately for it, the invisibility it inflicted Steve with works on it too, so he's able to get close while it's distracted with the others and attack it with a bazooka he imagines, hitting the control rune and breaking them free.
- Nightmare Weaver: The actual name of the demonic parasite that attacks the teams and traps them in their worst nightmares in order to break their minds down so that it can feed on them. It takes the form of a spider-like creature that appears gigantic in the Mental World but is actually only about six inches tall in reality.
- Post-Mortem Comeback: The Nightmare Weaver's attack was a contingency plan left behind by Norlock to kill anyone responsible for his death, complete with a recorded message to inform everyone of what’s about to happen to them.
- Seen It All: Steve notes that the Catastrophe, a house cat the size of a bus, isn't even the weirdest thing that Team Save Earth have seen this week.
- See You in Hell: Norlock's closing comment in his message.
- Ship Tease: Dib is notably much more assertive about saving Viera than any of the others, doing it solo while everyone just watches in surprise.
- Shout-Out:
- Whenever one of the characters starts fighting back against their nightmares, the figures in the nightmare point and shriek at them.
- The Nightmare Weaver turning out to be very tiny is a reference to a similar fear demon in an episode of Buffy the Vampire Slayer.
- "What Do They Fear?" Episode: Thanks to the Nightmare Weaver entrapping them, we get to see all the characters' worst fears:
- Zim finds himself back on Foodcourtia, having to deal with both Sizz-Lorr's aggressive management and a screaming crowd of customers.
- Skoodge is back on Blorch, being hunted by the Slaughtering Rat People.
- Tak is back on Planet Dirt, forced to clean up huge mounds of garbage that she ends up buried under.
- Tenn is caught by the Meekrob, who sentence her to being Devoured by the Horde of malfunctioning SIR Units that ruined her mission.
- Dib finds himself in a post-Alien Invasion Earth, about to be sentenced to death by Zim.
- Viera is mocked and harassed for believing in magic, which she can no longer remember having legitimate experiences with that can defend her views.
- Steve finds himself invisible and inaudible, completely forgotten about by Dib and Viera, before a crowd of people who can’t see him start literally walking all over him.
- Nyx's worst fear is being turned back into a mindless drone by the Control Brains.
- Gaz's nightmare is being forced back into the "Pig Girl" situation.
- Woken Up at an Ungodly Hour: Gaz is not happy when Nyx wakes her up at 2 in the morning to get her help.
