content: here they went in , and the cat stood with a cake of rye meal just below the door . suddenly there came a thundering and a thumping so that the earth trembled , and the whole castle shook , and that was the troll who was coming home . and suddenly all was quiet again , and before they knew it , helge - hal in the blue hill had thrust his three great horrible heads in at the door .
answer: a troll .
question: what was helge-hal in the blue hill ?
target: what was helge-hal in the blue hill ?
references: what was helge-hal in the blue hill ?