The Grim Adventures of Billy and Mandy Wiki
Series The Grim Adventures of Billy & Mandy
Season 6
Production code 621
Writer Nina Bargiel

Jeremy Bargiel Chris Mitchell

Broadcast information
Cartoon Network US Premiere November 9, 2007
Paired with El Dia De Los Muertos Estupidos
Chronological information
El Dia De Los Muertos Estupidos
The Grim Adventures of the KND

"Heartburn" is the 21st and final episode from season 6 and is followed by The Grim Adventures of the KND special.


Billy gets a camera from Grim's trunk that shows the true heart of those it takes pictures of. Mandy uses this in Irwin and is surprised with the results.


When Billy starts taking pictures with a camera found in Grim's trunk, Grim tells him that it's an Underworld's True-Heart Camera, which shows the real essence of a person's heart. When Mandy takes Irwin's picture, it is revealed that he is actually half-good and half-evil. Irwin explains that although he was born evil, his dad, Dick taught him all about love and respect, and he had a change of heart.

Upon knowing this, and against her own wishes, Mandy also experiences a disturbing change, turning good, innocent, trusting and warm-hearted. Mandy and Irwin finally share a romantic kiss in this episode, but it makes Mandy revert to her old dark and sinister self, which was Irwin's true intention, as he likes her just the way she is.





  • Story by: Bargiel Brothers and Chris Mitchell
  • Storyboard by: Chris Mitchell
  • Directed by: Kris Sherwood
  • Art direction: Marc Perry

Trivia & Goofs

  • This is the last regular episode of the series to air. However, the last regular episode produced was "Billy & Mandy Moon the Moon". After this, a special called “Underfist: Halloween Bash” was produced, originally as a pilot for a fourth installment in the franchise, but due to Atoms' contract expiration, it became the technical series finale of the show.
  • Mandy still rejects Irwin, even though she learned he is not just half-mummy but one quarter-vampire in "Dracula Must Die!" from his paternal grandfather.
  • The title of this episode is a reference to the acid reflux of the same name.
  • A lot of references to a "Colonel Major Cheese" character, being the mascot of a snack food of the same name are made. Whenever Billy took a picture of someone, he'd shout "Say 'Colonel Major Cheese!'" Irwin ate a bunch of bags of Colonel Major Cheese, and even rapped the commercial theme song, and later claimed it made him burp. This is a callback to the episode "Major Cheese".
  • Irwin reveals that he was devilishly evil, when he was first born, until his father disciplined him and raised him to be nicer, turning him into who he is now. This is most likely due to his mixed monster heritage of mummies and vampires.
  • General Skarr appears in the flashback of when Irwin was in the nursery. There, he had a full head of black hair and excitedly looked through the window at the newborns.
    • Given his age and the time period in this flashback, this meant that at some point, General Skarr was in Endsville, before the events of "Evil Con Carne".
  • Baby Irwin claws the skin off an airplane passenger's face, exposing his skull. The guy's skull bears resemblance to that of Grim's face, with it's only difference, being that it was slightly more elongated.
  • Irwin and Mandy kiss for the first time in this episode.
  • Before this episode first aired, a "deleted scene" from the episode "Keeper of the Reaper" was shown. The scene featured Billy calling Mandy's parents to the stand, where they broke the fourth wall, saying they don't appear in a lot of episodes because of their fear of Mandy. Then, they started making out.