- Mr. Bob
- Cafeteria lady
- Mrs. Blan
The episode begins with Noxxow and his lab assistants making an invisibility potion, with a secret ingredient of yogurt. Noxxow drinks it and starts causing trouble. At first, he scares Johnny by making it look like he is haunting the house, but Johnny later learns that he is just invisible. At school, Noxxow gets caught, but he shrinks Johnny so he cannot stop him. However, Charles reveals Noxxow by throwing some paint on top of him. Later, at lunch, Charles eats some yogurt, that happens to make him invisible!
- This is the first season 2 episode.
- Because of this, it is also the first episode with a title card.
- The episode is also known as "InvisiNoxxow."
- This marks the first and only time where Johnny sings like Mr. Skyheart.
- When Johnny ans Charles walk into the classroom, Charles turns sideways.