After setting their birthday with the NPC in Wedgehurst, if the player makes curry in the game on their birthday, a single candle and other party-themed things will be added to the Human curry.
In the Eastern side of the Hammerlock Pavilion there is a little girl who asks the player to deliver a message to her friend in Ballonlea. However, when the player delivers it to said friend, they find that he is actually a middle-aged man. Adding to the eeriness of the scene, the man claims that the girl who sent the letter was a friend of his who he hasn't seen since childhood. If the player returns to where the child was, she won't be there, and if the player searches the exact area she was on, they will instead find a hidden Reaper Cloth (An item important to Ghost-type Pokémon), implying she may have been a ghost. Furthermore, if the player goes back to the man's house, a child will be standing facing the wall and state that she is having a conversation with someone. This seem to be part of a string of similar "Ghost Girl" Easter eggs seen in recent main-line Pokemon games,
The Galarian Yamask has one of the most elaborate evolutionary methods in the entire series. In order to evolve it, the player must allow Yamask to lose 49 or more points of HP and then, with the damaged Yamask, the player must go under the large stone arch in the Dusty Bowl area. Immediately upon doing the latter, Yamask will evolve into it's Galar-exclusive Evolution, Runerigus.
In the games' data are the unused moves Celebrate, Hold Hands, Matt Block, and V-Create. They are not programmed to a single Pokémon in-game and Metronome will not turn into them.
Outside of Sirchester there is an NPC who states that he swam from the Kalos Region (from Pokémon X & Y) to the Galar Region. If what he says is true then this confirms that the two regions are in close proximity to each other just like their real-world European counterparts of the United Kingdom (Galar) and France (Kalos), which, in real life, are very close but separated by the English Channel.
There is a very rare chance that a Pokémon in the wild will come to the player's Pokémon camp while they are playing in it and ask to join the player's team. If the player selects the "Yes" option then not only will the Pokémon be able to join the camp but the Player will have also "caught" the Pokémon without battling it (it will go into one of the Player's Poke balls).
Japanese clothing company Uniqlo held a competition called the UT Grand Prix for a winner to have their artwork used for a t-shirt to be worn in-game and receive $10,000, with the grand-prize winner being Chinese artist Li Wen Pei. However, it was later discovered that Wen Pei had broken the contest's rules causing him to be disqualified and the grand prize not being awarded to another entrant. Though not explicitly stated by Uniqlo as to why he was disqualified, it's believed this was due to Wen Pei having used his design for his own commercial purposes such as on phone cases and t-shirts, which goes against the competition's rules. Wen Pei's design featured a Gyarados sitting atop a trio of Magikarp presented in a totem style.