What does blood sausage taste like?!

Rich, iron-y (it doesn't taste of irony as I wrote first time), earthy, meaty. Not very helpful words but it's difficult to describe

Edit - to answer your follow up questions yes, it's safe to eat if you get a good one from a butchers and cook it properly. I fry mine.I love it, and regularly have it as part of a weekend breakfast, perhaps with some fried eggs or a muffin.