Mariah Carey and McDonald's have a partnership titled, McDonald's Mariah Menu.
The collaboration features 12 days of free food deals.
Today (Tuesday) if you ordered a Sausage McMuffin with Egg in the app you got a free Mariah/McDonald's shirt.
The shirts went to the first 10,000 people who ordered.
The black shirt comes in one size (large) and features Mariah eating a McDonald's meal.