"its name is Dracunculus borealis, the Arctic worm"

Although Dracunculus is a real genus of a parasite, and the species Dracunculus medinensis (commonly known as Guinea worm) does exist, Dracunculus borealis belongs to the realm of licentia poetica. The ancient Arctic worm was created by Peter Høeg for the purpose of this book - or at least not discovered by scientists... yet.