Nothing is known about the past of Nimri, yet. What is certain is that he was something different before. Naldela still speculates what he might have been, and based on his behavior she estimates that he was a male human-like being.

When he met Naldela on her way to the surface he was starving and so grateful that she gave him something to eat that he started to follow her out of guilt.

More about him on teleyal.blog