In that particular area of DB, theres normal Jormungar worms and then these guys which are like the larval stages of the adult ones. Shame they arent tameable, they're my favorite larva skin
As Equeon said, they often go unnoticed but mostly cause the goblin trio Narf, Zort, and Troz who sits right where these guys romp around have no quests that lead to them (that ive come across anyways when questing) and they and the harpies they ask you to kill are in general in a nearly no-traffic area ^^ Even when flying overhead I often dont notice them down below on the minimap or on the ground.
Regardless though, shedding new light on these guys is awesome since they really do go unnoticed and are a gorgeous combination of grey and blue! One day.. one day i hope they will be tameable..