It is a pure animal product, with no cereal or filler in it. It is made from blood, fat and tongue spiced with ground black pepper.
The sausage is cured and dried, so that it is safe to eat without cooking first.
Some like it as a cold meat for sandwiches though it is also often fried up.
It is often sold already sliced.
“Zungen” means “tongue”; “wurst” means “sausage”.