Nebby (anime)

This Solgaleo, nicknamed Nebby, is a /-type Legendary Pokémon in the anime.

Personality
Much like Ash's Noivern when it was a Noibat, Nebby unleashes a high pitch scream when it gets upset. Nebby is also very friendly to those around it and is very playful when using Teleport on its friends with a smile on its face. It is also very picky about food and only eats star-shaped candies. It sometimes Teleports away just to get its favorite food.

Nebby has a close bond with Ash seeing him as a parental figure and their closeness is seen when Nebby uses it's powers to teleport back to Ash on it's own. It even has a close friendship with Pikachu and Rowlet as it spends the most time with them as it likes to sleep with both of them although it takes turn on who to sleep with also it likes playing with them as well.

It is also very curious when reading the thoughts of others teleporting Ash and his friends to various places wishing to see the outside world even though if it's aim is off. In the end of SM045, Nebby was revealed to be mischievous as it cries and teleports everyone at the top pillar of the Pokémon school to make them horrified on Nebby's reading from their thoughts.

Nebby is also helpful at times, when it answered Lillie's desire to see her brother and when it tried to teleport them away from danger.

As Cosmog
Nebby first appeared in Ash's dream where he witnessed it being created by Solgaleo and Lunala. Then, on his way to the Pokémon School Ash and Pikachu see Tapu Koko who led them to Cosmog and they found it sleeping. Once Ash arrived at the Pokémon School, he showed his classmates the little Pokémon and they are amazed at the discovery. However, when it woke up, it let out a high-pitched scream whenever it cried. After calming it down, Lillie decided to name it Nebby while Ash decided to take care of it as he made a promise to Solgaleo and Lunala to take care of it.

Nebby was revealed to have learned Teleport and teleported Ash and his friends to various places. But also causes mischief in the end when it cries and teleports them into the top pillar of the Pokémon school much to their scare.

Nebby comes with Ash and the gang as they visit the Aether Foundation, Faba wishes to see Cosmog but as he tries to come closer it teleports away. As the kids were enjoying the food, Nebby tried to eat a big bowl of sugar stars until it was stopped by Ash before it gets a stomach ache. Then, it teleports all over the place taking sugar stars from Team Rocket and teleports back to Ash before the trio can catch it.

Nebby teleported Ash, Pikachu and Lycanroc to Gladion's location where they came across him and his Type: Null. This frightened Nebby, causing it to cry until, Pikachu calmed it down, and went straight to sleep. During a battle between the two trainers, Nebby woke up by all the commotion and let out a high-pitched scream, which knocked Pikachu back and got Lycanroc's fur clean. Pikachu praised Nebby for calming Lycanroc down, and when Ash realized how long he's been gone, he asked Nebby to teleport them back home, but it went back to sleep.

Nebby gets examined by Professor Burnt who gives it a clean bill of health and has grown to like her. Then, at the sleepover Nebby had fun playing a game of hide and seek with Ash and his friends and after the sleepover hearing Lillie's desire to see her brother Gladion. It teleports her to him then back to her friends but Nebby's actions cause Lillie to become fearful of Pokémon again.

In an effort for Lillie to get over her fear Nebby teleports her, Ash, Pikachu, and Snowy to various places from Lillie's memories as a child. Once they all made it to lab at the Aether Foundation, Faba tried to kidnap Lillie in an attempt to erase her memory. Nebby tried to teleport them away from danger but they were restrained Faba's Alakazam; when Gladion's Sivally saved them and Lillie retained her full memory, she finally overcome her fear of touching Pokemon and Nebby was very happy for her.

Later, Faba successfully captured Nebby by tempting and feeding it candies and took it to his lab for experiments. After Ash and gang successfully stopped Faba and freed Nebby, it evolved into a Cosmoem.

As Cosmoem
After what happened at Aether Foundation Ash becomes worried about Nebby since it hasn't moved. When Ash and his friends discover that Lillie is nowhere to be found they talk with Kahuna Hala and from him they all head over Poni Island and then the Altar of the Sunne in the hopes of finding Solgaleo but they find all Tapu Guardians there instead.

As Solgaleo
Nebby evolved into Solgaleo in episode 52. Ash showed to Tapu Koko that Nebby has evolved. When they saw it, they moved to their pillars and  released light from Altar of Sunne  to help Nebby to evolve into Solgaleo.

Trivia

 * Nebby shares some similarities with Squishy:
 * At their first appearance, neither one of them were recognized by the Pokédex in the anime.
 * Both of them are Legendary Pokémon being cared for by a main character; Bonnie took care of Squishy and Ash is taking caring of Nebby respectively.
 * Both of them were used to fulfill the plans of an evil organization.
 * Both were given nicknames because they weren't recognized by Pokédex.
 * Like Squishy and Meloetta, Nebby is a Legendary Pokémon traveling alongside the group.
 * The way Ash holds Nebby (as Cosmog) is similar to how Misty held her Togepi and Azurill and Brock with his Happiny.
 * Nebby (as Cosmoem) shares some similarities as Ash’s two other Generation I Pokémon’s mid-evolve forms, Butterfree (as Metapod) and Charizard (as Charmeleon). Both of these three Pokémon are mainly have less episode appearances of their mid-evolve forms:
 * Like Metapod, Nebby’s mid-evolved form is also at an immovable state.
 * Like Charmeleon, Nebby’s mid-evolved form only appeared in 3 episodes, where they both evolved in their last third episode appearance.