"To commemorate National Hairball Awareness Day, the museum featured a display of 10 of these hairballs"
Hairballs: Myths and Realities behind some Medical Curiosities (possibly NSFLunch) [more inside]
Doctors remove a ten-pound hairball from an 18-year-old girl's stomach. It's still not the world's largest - that one came from a cow and weighed 20 pounds. And this homemade one doesn't count.