The traditional Yorkshire pudding is actually just pastry and is capped off at the top, so no space to put anything inside it. It's more solid. I hadn't been aware of these new-fangled fill 'em with sausage versions until this thread. But then Yorkshire puddings of any kind were never part of my Sunday dinner growing up. So I'm definitely no expert on them.
With these new versions they seem to be trying to ape our traditional Scotch Pies.
Yes, black pudding is made with blood. I've never eaten any, always loathed it. Fruit pudding is a kind of doughy, suet version, with raisins and sultanas etc, which you slice up and fry with the usual fried breakfast ingrediants and that is delicious, I have to say.
As for haggis - I'd recommend giving it a go. I avoided it for decades because of its origins and then recently I was persuaded to try it by Stuart, who had been converted himself by a workmate cooking it for dinner at the fire station. And I have to say it's pretty dang tasty. Just like a spicy mince. Wonderful with mashed potatoes and turnips.
LabRat
