Nim didnt die. You need to watch all the episodes. Im not even sure what you could do to kill one of the creatures. There was that one dead one they had to study early on but they never really gave a clear cause of death for it. The gaurd put a round in the little dude and I even thought he was done at the time. However the little guy ended up living in the aquarium and later thy released him to track him to the school of creatures. Then the stupid gun toting red necks get thier asses nearly eaten alive when the kid shows up and talks pissed little Nim and down and shows a little beast mastery over his new kindred. Nim is alive and well in the last episode.   See 3 other replies