Older people in my family think it's absolutely ok to eat Schwarzsauer. It's soup made with pigs' blood and rests of pork, you know, that meat that can't be used for anything else, not even sausages.
Not happy with it, people also make Blutwurst, blood sausages. We also have Leberwurst, a sausage made with pork liver and other meat that you don't really want to know.
There's also Sülze or Presssack, it's made with some sort of colorless gelatinous substance found in the head of pigs, sheeps, cows or calves after the brain is removed. Some sorts of Presssack are pink/red because people add blood to it. It's eaten cold and looks like some sort of very macabre jelly with disgusting pieces of meat in it. My mother loves to cut it into slices and eat it on bread.
Other thing people in my family like to eat is Schmalz, which is cold goose/chicken/pork grease and skin-fat, spread on bread.
And of course, I've eaten all of this stuff at some point in my childhood because at home you can't reject food before trying it out. And then throwing up to let your parents know you absolutely don't like it, because only telling them doesn't work .
Germans eat the most exotic (here meaning "gross") stuff in the world, I swear.