Nocturn

The Nocturn is an enemy found in Spirit Tracks. It is encountered in the Tower of Spirits on the third visit. They will hover out of reach in the darkness, but when they suddenly get exposed to the light, they fall to the ground, weakened. This can easily be done by lighting up the torches around with the boomerang or by using Princess Zelda to possess a Torch Phantom to move around with a light. Once this is done, Princess Zelda or Link can attack the Nocturn.

Trivia

 * Its name is derived of the word nocturnal, referring to the fact that they live in the dark and resent the light.