|Nigel Planter and the Chamber Pot of Secrets|
|Series||The Grim Adventures of Billy & Mandy|
|Writer|| Maxwell Atoms|
|Cartoon Network US Premiere||July 16, 2004|
|Paired with||Circus of Fear|
Circus of Fear
Billy, Mandy and Grim are playing golf when they encounter boy wizard Nigel Planter again (who somehow survived his beatings from the giant one-eyed dwarf.. Nigel reveals that he is unable to stay at Toadblatt's School of Sorcery because he is being hunted by the feared Lord Moldy Butt (with the mere mention of his name causing things to break). Nigel asks the trio to accompany him back to Toadblatt's and be his security. The gang arrive in Dean Toadblatt's office and find Toadblatt suspiciously acting kindly towards Nigel (as Toadblatt has previously made his contempt for Nigel known). Later that night, back at Weaselthorp House, Lord Mouldy Butt sneaks into Nigel's dormitory and warns him to stay away from the Chamber Pot of Secrets in Toadblatt's office. Lord Mouldy Butt attempts to throttle Nigel but is spotted by Mandy. He escapes, but leaves a strange powder behind.
As Mandy and Grim begin their investigation, Billy accompanies Nigel to school and stands guard outside Nigel's classroom, but Lord Mouldy Butt manages to sneak in and again warn Nigel to stay away from the Chamber Pot of Secrets. Nigel is summoned to Toadblatt's office, where Toadblatt informs him that he will have to leave the school as they can no longer protect him. As Toadblatt is saying goodbye, Lord Mouldy Butt appears from the Chamber Pot of Secrets, but Mandy reveals that it was a costume Dean Toadblatt had been using to terrify Nigel. Mandy reveals that the dust Lord Mouldy Butt left at Weaselthorp House was actually from a latex mask, and hair and fingerprints collected from Nigel's room matched that of Toadblatt.
Toadblatt confesses and admits he did it in order to get Nigel removed from the school. Nigel gains his revenge by shrinking Toadblatt to the size of a golfball, which Grim uses and ends up hitting Toadblatt towards a French restaurant. Just as Nigel claims he knew there was no real Lord Mouldy Butt (which causes Mandy's golf club to break), the camera pans down to the centre of the Earth where the real Lord Mouldy Butt vows to find Nigel
- Story by: Maxwell Atoms, Mike Diederich
- Storyboard by: Mike Diederich
- Art direction: Rae McCarson
- Directed by: Shaun Cashman
- The name of this episode is a parody of Harry Potter and the Chamber of Secrets, with Lord Moldy Butt acting as a parody of Lord Voldemort.
- Billy's wand is similar to that of the fairies from Nickelodeon's The Fairly OddParents.
- The classroom of Squidhat's Voodoo Class is numbered 101. This is a possible reference to the "Room 101" torture chamber - where a prisoner was confronted by their worst nightmare or phobia - from George Orwell's dystopian novel Nineteen Eighty-Four.