Black pudding or (less often) blood pudding is a British English term for sausage made by cooking blood with a filler until it is thick enough to congeal when cooled. It is also called blood sausage (first attested in 1868, perhaps influenced by German Blutwurst). Although "blood sausage" is often labeled as a North American term, it is also found in British English (e.g., in the story "The Name-Day" by Saki). "Blood sausage" is also a useful term for similar blood-based solid foods around the world.

Pig or cattle blood is most often used; sheep and goat blood are used to a lesser extent. Blood from poultry, horses and other animals are used more rarely. Typical fillers include meat, fat, suet, bread, sweet potato, barley and oatmeal. 

Yuck!