Also nicknamed in some places "blood puddings", some people I've spoken to (namely Americans) immediately think of a sponge pudding that's full of blood that makes them recoil in horror and disgust at the thoughts of it.
Black Puddings are an invention from my home town of Bury. It's a combination of pig fat and pig blood that's been pre-cooked and is sliced and fried or grilled. Since pig blood isn't commonly found in local butchers or supermarkets the black pudding is bought already prepared and ready to cook. It's traditionally served as part of a cooked breakfast consisting of any or all of bacon, sausage, baked beans, fried/poached eggs, fried mushrooms, fried tomatoes, hash browns, and a slice of fried bread.
The consistency of a black pudding is soft and crumbly and can be quite brittle so care is needed in both cooking and serving it. Its appearance is like a large black sausage, hence the name "black pudding." The taste I couldn't tell you as I don't like them, I remember trying a tiny bit as a child from the black pudding stall in Bury's famous outdoor market and I didn't like it and immediately spat it out, plus I remembered reading in the Bible not drink the blood of animals so that made me feel uncomfortable even trying it. My husband says it tastes a bit like fatty pork so I'll just have to take his word for it.