Eclipse is a NightWing of unknown gender who is appeared in Darkness of Dragons. They were shown attacking the IceWings at Jade Mountain with Smokeseer. They appeared when Moonwatcher tried to convince them to stop attacking.
Eclipse was shown attacking Narwhal and Snowfall alongside Smokeseer. They were mentioned by Moonwatcher and Eclipse may have been the one to yell at her, saying "They want this war! We're defending ourselves and you should be fighting alongside us, traitor!"