|Living:||The Beginning, Kits and She-Cats, Night Calls, Rising Troubles, Snowsong's Secret, A New Moon, Goldenflower's Love, Pantherkit's Escape, Ravenfeather's Gift, Adderkit's Betrayal|
Nightfern is a beautiful, thick-furred slender silver tabby she-cat with dark blue eyes, white ear tips, and dark grey paws. She is the most gorgeous cat after Ferns of Night that the Clans have ever seen.
Nightfern was born to Icefur and Stormpelt. Her mother was a ThunderClan cat who had been captured by Twolegs and raised as a kittypet for a moon. When she escaped, she met her father, Storm, a loner. They fell in love and soon Icefur gave birth to six kits, including Night. Icefur and Storm were far away from the lake, so they didn't know where to go. Night and her siblings lived in peace until the time came when the family was starving. ThunderClan cats, still looking for their missing Clan mate, found their long-lost warrior and her mate and welcomed her, Storm, and her kits to the Clan. Nightfern became an apprentice a few moons later and was mentored by Hollystar. She became a respected warrior of all the Clans, because she was easily the most powerful she-cat in the forest despite her slender shape and temper.
Snowpaw becomes her apprentice and the two distant relatives form a bond quickly, working together to raise Snowpaw as a beautiful and powerful she-cat. Later on, Nightfern watches Snowpaw's reflexes as discovers they are as quick as she expected. She mentions her apprentice has not caught a mouse in some time, probably because of her snow-white pelt. Nightfern goes hunting with Snowpaw and catches three mice and a plump thrush. Nightfern is delighted with how much they've caught together, and is horrified when back at camp, she discovers the elder Greenflower has blackcough. Days later, Nightfern watches the birth of Hawkkit and Ivykit.
Nightfern hears a delighted yowl from the nursery and goes into it. Amberheart is revealed pregnant with Bramblefur's kits and Nightfern is proud for her sister.
A moon later, Nightfern is seen worried about her sister's due date when a huge storm hits. Nightfern, feeling as if an unnatural urge was bring her to see her sister. She sees Amberheart panting and in pain and asks what's wrong. Amberheart responds she's due to kit soon, and Nightfern sleeps with her sister, still feeling uneasy. She wakes up a while later, hearing a yowl of distress, and bolts out of the nursery to see Brackenheart crushed by a tree hit by lightning in camp. She alerts the warriors. Brackenfur, being slowly sucked up by the mud, is dying and Nightfern grabs his scruff in effort to save him. She's too late; Brackenheart is dying rapidly. She turns away, unable to bear the sight, but is met by another agonized yowl from the nursery. She flees to the nursery, where the queens are helping Amberheart in labor. Nightfern instantly recognizes this kitting is much more dangerous that Featherfoot's. Amberheart is pouring blood and nothing can stop it. Nightfern is terrified for her sister and the unborn kits. Amberheart gives birth to a kit, which Nightfern licks and nudges, but the kit dies heartbeats after coming into the world, to Nightfern's horror. Amberheart goes into stronger labor and gives birth to another black kit, which Spottedstripe tries to save. The kit is stillborn. Amberheart, screeching and screaming, finally bears a last kit.
Nightfern, determined that this kit lives, pushes it into her fur and licks furiously. Amberheart, in pain and confusion, asks to see her kits. Nightfern painfully replies there is only one, to which the not-quite-stable Amberheart argues there are three.
Nightfern lets the kit suckle, and Amberheart asks her to name the only kit. Nightfern names her Moonkit. The dead kits are named Shadekit and Jetkit, in honor of their black pelts. Nightfern, grieving, leaves the nursery only to find Brackenfur died from the tree and injuries. Hollystar asks Nightfern to announce the news, to which Nightfern agrees and tells the Clan of the birth.
The next morning, Nightfern wakes up, angry and lonely when the day is beautiful, blaming herself for the kits deaths. She leaves the warriors den and goes to the nursery to help. Amberheart is delusional and asks again to bring back her deceased kits. Fawnpelt shoos her out of the den and tells her to bring back poppy, catmint, watermint, and mice, as well as nectar if it's possible.
Nightfern kills three deer mice and a sparrow in one strike by crushing them and hides them in the dirt. She scents sweet honey nectar, and finds a large bee cone in a tree. Knowing it could help Amberheart will the liquid, she drops the mints, unable to find poppy, and grabs the cone, snatching the mints fleeing to camp while bees attack her. She returns to camp and leaves the supplies on a shard of rock, where Spottedstripe is nursing Amberheart back to health. Spottedstripe reveals Fawnpelt and Featherpaw went to Moon Rocks to speak to the recently deceased. Nightfern feeds her sister, who thankfully snaps out of her limbo state, and sleeps peacefully.
- Nightfern originally had a sister named Leafblossom; however, because Leafblossom was never mentioned and was mistakenly the mother of Ripplepaw, (a error in the first book), she was deleted from alliances and never mentioned again.
- Nightfern's brother, Breezetail, was originally named Nightbreeze until October 2011, when Nightfern realized that only the kai could begin with "Night".
- Nightfern was originally called Silvercloud in her email-stories with Ottersplash before Nightfern created an account and therefore, Silvercloud was changed to Nightfern.