Nebby/Games/SM

During the opening cutscene, three months prior to the beginning of the undefined'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  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 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, 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, and curiously approaches the player. Later, at the Ruins of Life, Olivia suggests that Nebby must be powerful when it approaches 's territory.

On Ula'ula Island, Lillie informs the player that she and Nebby intent to see the Ruins of Abundance. However, when at the Aether House on, they are kidnapped by Team Skull in an operation led by Plumeria. At Aether Paradise, Nebby is subjected to Team Skull and the Aether Foundation's experiments aiming at opening more Ultra Wormholes and harness the power of Ultra Beasts&mdash;experiments Lillie had originally saved it from with their escape seen during the opening cutscene. When Lusamine abuses Nebby's powers to open Ultra Wormholes, it is revealed to have evolved into (although no one is seemingly aware of this). After Lusamine and Guzma have left Aether Paradise through an Ultra Wormhole, Lillie is able to take back Nebby.

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 helping Nebby do not come true, she is given the Moon Flute or Sun Flute. At the Altar of the Sunne or Altar of the Moone, Lillie and the player play the Sun Flute and the Moon Flute together during the daytime or nighttime, and Nebby is drawn from her bag, evolving into or. Upon Lillie's request, Nebby guides her and the player into Ultra Space. In Ultra Space, Nebby roars at Lusamine who has merged with, 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 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).