What is a Hornless breed of cattle with shaggy black coat bred for beef?

The breed you are describing is likely the Highland cattle.

Here's why:

* Hornless: While Highland cattle typically have horns, there is a polled variety, meaning they are naturally hornless.

* Shaggy black coat: Highland cattle are known for their long, shaggy coats that come in various shades, including black.

* Bred for beef: Highland cattle are a beef breed, valued for their rich, flavorful meat.

While other breeds might share some characteristics, the combination of a hornless variety, a shaggy black coat, and beef production makes Highland cattle the most likely answer.