Hahaguffawchuckleamalus

The Hahaguffawchuckleamalus is a purple brain lobe that appears only in Captain Underpants: The First Epic Movie. The size of the lobe determines a person's capacity for laughter. People with large Hahaguffawchuckleamaluses have a huge sense of humor, while those with small or no Hahaguffawchuckleamaluses are humorless.

Professor Poopypants's goal in the movie is to shrink or even remove the Hahaguffawchuckleamalus, ridding the world of laughter in the process.