Japanese Title: Satoshi and Hoshigumo! Mysterious Encounter!!
Original Airdate: October 5, 2017
US Airdate: March 24, 2018
After a dream involving the Legendary Pokémon of Alola, Ash comes across a mysterious little Pokémon whom Lillie calls Nebby. Its appearance draws the attention of the Aether Foundation, led by Lillie's prodigal mother, Lusamine. They are concerned that Nebby might have something to do with the Ultra Beasts, mysterious creatures that occasionally roam Alola.
This episode contains examples of the following tropes:
- Amazingly Embarrassing Parents: Lusamine is definitely this for Lillie.
- Doorstop Baby: Ash and Pikachu found Nebby in a forest near the Pokémon School.
- Early-Bird Cameo: We get brief glimpses of all the Tapus, including the previously-unseen Tapu Fini and Tapu Bulu.
- G-Rated Sex: Solgaleo and Lunala are shown creating Cosmog. Right in front of Ash. They do so by beaming energy at each other, where Cosmog is generated at the point where their energy beams meet.
- Inelegant Blubbering: Nebby's Ocular Gushers could be weaponized with the shrill noise it makes.
- Interface Spoiler: The "Who's That Pokemon" segment in the Japanese version lists Nebby with its species name. The dub avoids this, first pausing out of uncertainty, and then calling it by its nickname in quotation marks.
- Lampshade Hanging: When Nebby falls asleep at the end, RotomDex notes all the chronic oversleepers already at home.
- Logic Bomb: RotomDex does not see the logic of Ash making a promise in a dream.
- My Significance Sense Is Tingling: The moment Cosmog is conceived, all the Tapus are stirred awake.
- Related in the Adaptation: In their first appearance together in the anime, Professors Kukui and Burnet are merely acquaintances.