Nebby (Japanese: ほしぐもちゃんHoshigumo-chan) is a character introduced in Pokémon Sun and Moon. Although it seems to possess a mysterious power, being a Cosmog, Nebby is depicted as frail and unable to use moves for large parts of the games' storyline. Nebby's name has been given to it by Lillie, who cares for it and tries to find out about its true nature. In an attempt to save it from harm, Lillie often keeps Nebby in her bag in order to hide it from outsiders.
During the opening cutscene, three months prior to the beginning of the player's adventure, when Lillie tries to flee Aether Paradise, she is teleported away by a mysterious force; that force is later revealed to stem from Nebby, who hid in her bag. Lillie and Nebby wash up on a beach, where they are found by Professor Burnet, who agrees to help Lillie learn more about Nebby. She then contacts her husband, Professor Kukui, who allows them to stay with him for the time being.
The player first meets Nebby on the Mahalo Trail, being informed by Lillie that it is being attacked by a group of wildSpearow on an unstable rope bridge. When the player steps in to protect it, Nebby is forced to use its hidden powers, thereby destroying the bridge. It is saved by Tapu Koko while falling. When asking Nebby to return into her bag, Lillie also asks the player to not tell anybody about Nebby. At the Iki Town festival, Nebby watches the player receive their starter Pokémon, and later their Z-Ring. Nebby is with Lillie when she introduces Kukui's lab, the Pokémon Center on Route 1, the Trainers' School, and Hau'oli City to the player.
When the player arrives at Melemele Meadow, Nebby has escaped from Lillie's bag. However, the player can find it unharmed; Lillie then asks Nebby to return to her bag. After the player has completed Hala's trial, Nebby and Lillie accompany the player and Professor Kukui to Akala Island.
At Akala Island, Lillie believes Nebby might be interested in visiting the Ruins of Life. Nebby is next seen at Dimensional Research Lab, where it fails to adhere to Lillie who instructs it to use Splash, and curiously approaches the player. Later, at the Ruins of Life, Olivia suggests that Nebby must be powerful when it approaches Tapu Lele's territory.
In order to make Nebby feel better after the events at Aether Paradise, Lillie travels to Poni Island. Although at the Ruins of Hope, her hopes of Tapu Fini helping Nebby do not come true, she is given the Moon FluteS or Sun FluteM. At the Altar of the SunneS or Altar of the MooneM, Lillie and the player play the Sun Flute and the Moon Flute together during the daytimeS or nighttimeM, and Nebby is drawn from her bag, evolving into SolgaleoS or LunalaM. Upon Lillie's request, Nebby guides her and the player into Ultra Space. In Ultra Space, Nebby roars at Lusamine who has merged with Nihilego, forcing the two apart. Afterwards, Lillie informs the player that Nebby wants to keep on traveling with her and the player; however, Lillie stresses that she is not a Trainer and urges Nebby to join the player. A battle is initiated, and the player is then required to catch Nebby (and in the process, they can give it any nickname).
Nebby plays largely the same role in Pokémon Ultra Sun and Ultra Moon until it evolves into SolgaleoUS or LunalaUM, where it briefly does battle with Necrozma and loses. This allows Necrozma to absorb Nebby and turn into Dusk ManeUS/Dawn WingsUM Necrozma and attack the player. After defeating Ultra Necrozma at Megalo Tower, Nebby is freed from Necrozma and returns to the Altar of the SunneUS/Altar of the MooneUM. After thanking the player, Lusamine and Lillie take Nebby to Aether Paradise to be treated.
After the player defeats Ilima during Mina's trial, they have the option of returning to the now-repaired Mahalo Trail Plank Bridge, where Lillie will ask the player to take Nebby in their care.
Nebby first appeared in The Decision and the Tournament of Six, where it escaped from Lillie's bag and ran off to Mahalo Trail, where it was attacked by a group of wild Spearow. Lillie was too scared to help it, so Moon stepped in to save Nebby in her place. When she got to Nebby, it retaliated against the Spearow by releasing a shockwave, causing the bridge they were standing on to break apart underneath them. Moon and Nebby were rescued from falling in the water by Tapu Koko, who caught the two and brought them back to safe land.
In PASM14, Professor Burnet accidentally caused Lillie to recall painful memories of a traumatic experience caused by her mother, Lusamine. Lillie's distress caused Nebby to fly out of her bag and begin clawing at the sky, nearly creating an Ultra Wormhole. After Lillie fainted, Nebby stopped and went down to check on her out of concern.
In PASM17, after Sun completed his second trial at the Thrifty Megamart, he thanked the Rotom Pokédex for its help in the battle where it gave information about Tapu Bulu. To Sun and Lillie's surprised, Rotom revealed it learned about Tapu Bulu from Nebby. Hoping that Rotom could translate Nebby's speech and speed up his job to deliver Mirage Berries to each of Alola's guardian deities, Sun tried to get Nebby to come out. To their shock, Nebby emerged from Lillie's bag in the form of the motionless, cocoon-like Cosmoem.
Later, after arriving on Poni Island, Lillie and Gladion took Nebby with them as they traveled to the Poni Altar. A Xurkitree attacked the duo as they passed through Poni Wilds, forcing Gladion to battle it with Silvally. During the clash, Nebby flew out of Gladion's grasp and into the air where it reunited with its fellow Cosmog, who had also evolved into Cosmoem. The two Protostar Pokémon flew towards the Altar. Upon arriving, the guardian deities took Sun and Moon and placed them on the Altar with the Sun and Moon Flutes. By playing the flutes together, Sun and Moon caused the Altar to react and release a light that hit both Cosmoem.
Lunala merged with Necrozma
The light caused Nebby and the other Cosmoem to evolve into Lunala and Solgaleo, respectively. With its newly-gained power, Lunala put Moon on its head and helped fend off the Ultra Beasts that had arrived to attack the Poni Altar. Shortly after, a larger than usual Ultra Wormhole appeared at the Altar with a Necrozma's hand emerging from it. The hand took control of Solgaleo's body. The possessed Solgaleo grabbed Sun with its tail and jumped into the wormhole. Lunala activated its third eye and flew into the wormhole with Moon still on its head.
Some time after arriving in Ultra Space, Lunala got separated from Moon and Sun. At some point, it came in contact with the Ultra Recon Squad, who used Lunala to traverse through Ultra Space via Ultra Warp Ride. At the Ultra Deep Sea, Lunala reunited with Sun and Moon, who had been trapped in the area for six months. After agreeing to work together, Sun, Moon, and Zossie rode on Lunala's back so they could return to Alola. Dulse stayed behind as Lunala couldn't carry more than three people on it. Zossie taught Sun how to use Ultra Warp Ride and told him and Moon about the various worlds the Ultra Beasts come from. After passing through an Ultra Wormhole, the three arrived at the Ultra Recon Squad's home world, the Ultra Megalopolis.
Shortly after landing, a Stakataka appeared, hoping to battle with Necrozma. After it captured Sun, Stakataka attacked Moon, but she was protected by Lunala. Moon commanded Lunala to battle Stakataka, but it was unable to use its full strength without risking Sun's safety. By firing an arrow at the Zygarde Cube in Sun's bag, Moon released several ZygardeCells that stuck onto Stakataka's eyes, blinding it and allowing Lunala to easily finish it off. The battle alerted Necrozma, who released Solgaleo and leapt from the Megalo Tower to try and absorb Lunala as well. Lunala tried fighting back, but was overpowered. Sun and Moon sent out their Pokémon to help, but were stopped by Lusamine. Eventually, Lunala was absorbed by Necrozma, causing the latter to become its Dawn Wings form.
Personality and characteristics
As a Cosmog, Lunala was easily overwhelmed and would often become frightened in stressful situations. When afraid, it would accidentally open Ultra Wormholes. Despite this, it would still try its hardest to protect others from danger. After evolving into a Lunala, the Moone Pokémon became much more brave, quickly jumping in to save others. Lunala has developed a close bond with Lillie, Sun, and Moon.