Tjorven the Cat
Tjorven is Hedeby's resident stray feline. She makes friends with Blomkvist on his first night in town. Sadly, Tjorven becomes Martin's victim when the nutso man burns and mutilates her, presumably to try to scare Blomkvist off the case, or to provoke him into a confrontation. Tjorven's relationship with Blomkvist increases sympathy for him as a character, and her tragic death signals us that the novel is taking a much darker turn.