Captain Nils Helstrom is the main antagonist of the 1933 adventure/family film The Son of Kong. He was portrayed by John Marston.
Nils Helstrom is a Norwegian skipper who had lost his ship under questionable circumstances. He killed Hilda's father during a fight.
He was the man that sold Denham the map to Kong's Island, and after meeting him again he convinces him that there was a treasure on the island. Denham agrees to go back and try to retrieve it. However, during the journey, Helstrom incites a mutiny on board their ship. But the sailors want no more captains and throw him overboard alongside Denham, Hilda and some others. They arrive on the island and discover King Kong's son and the treasure, but Helstrom is killed by an Elasmosaurus near the end of the film.