Any of various marine (chiefly deep-sea) polychaete worms which comprise the genus Osedax and live on the bones of dead whales (and possibly other marine vertebrates).
2005
A strange assortment of creatures then colonized the bones.., including several new species of the bone-eating zombie worm.
Science 25 February 1191/2
2015
Scientists found that Osedax—popularised as the ‘zombie worm’—originated at least 100 million years ago, and subsisted on the bones of prehistoric reptiles.
Belfast Telegraph Online (Nexis) 15 April
Originally published as part of the entry for zombie, n.