With their tender texture and unbeatable flavor, beef oxtails are the perfect meat for a hearty, slow-cooked soup or stew. What is oxtail meat? Oxtail comes from the gelatin-rich tail of the cow and is an excellent source of protein and a good source of iron. As beef oxtails cook, their flavorful marrow releases tons of rich flavor, and the meat becomes fall-off-the-bone tender.