Costco recalled 80,000 pounds of butter whose packaging omitted the allergen warning 'Contains Milk.' It follows a far worse packaging error from Mattel last week.

Costco voluntarily recalled 79,200 pounds of two types of its store-brand butter over the past month because their labels may not have said the products contain milk.

Costco's latest recall, which includes some 80,000 pounds of butter, has given the internet a reason to mock the beloved warehouse giant. Here is everything you need to know.