This hatchling appears to be... dead?

Perhaps not. It seems to be active during the night.

Young dragons are relatively defenseless. They are born with relatively soft scales, which are shed and replaced with harder ones as the hatchling matures. Once a hatchling’s wings grow in, it typically marks the beginning of maturation. At this point they are often capable of hunting on their own and are usually left alone by their mother.

Volti's intentions are nowhere near as evil as her foster parents, Voltera and Vulturi. Being still a hatchling, her taste for dragon blood hasn't fully developed. Sometimes, under the watchful eye of a guardian, she is allowed to play with the other frozen hatchlings. So far she has show no aggression, and some of the more brave hatchlings like her.