Easter Eggs

Easter Eggs are hidden parts of a game that are mostly found through player characters experimenting or boredom.

Red/Blue

• Though this may be a glitch, the player character can escape the final fight with the ghost in Lavender Town inside the Pokémon Tower.
• Though is most likely a glitch, the player character can use the move Cut on tall grass in order to pass through.
• One of the game consoles inside one house has text that reads "A game with MARIO wearing a bucket on his head!". This could reference the game "Mario and Wario" or could just reference the Nintendo character Mario.
• Similar to the above Easter Egg, the music for Route 24 is similar to some of the level music from "Mario and Wario".
• Though this may be a glitch, X Accuracy raises accuracy to the max instead of raising it by one stage like other X items do.

Hey You, Pikachu!

• If "Playstation" is spoken in the mic, the Pikachu will become angry, representing Sony's and Nintendo's rivalries. This is believed to be a coincidence, mostly due to the fact that, in the games full vocabulary, the words "PlayStation" and "Sony" don't even appear, with many believing these words were interpreted by the game as words in the library that anger Pikachu

Diamond/Pearl

• After a player character defeats the Elite Four, if the player character talks to Dawn or Lucas (depending on their gender) on their birthday, they will wish the player a happy birthday.
• If you walk a certain distance from a Hiker, they'll appear to look shocked.
• In the Lost Tower, there is a Roughneck named Kirby. The Pokémon that he sends out is a Cleffa, which resembles the character Kirby, from the Kirby series games.
• Somewhere outside of Canalave City, a guard says "Boy... I sure am thirsty...". This is a reference to the thirsty guards outside of Saffron City in the Kanto games.

Black and White/Black 2 and White 2

• The music for Floccesy Ranch is very similar to the hiker theme in Pokémon Diamond, Pearl, and Platinum. This is likely a reference to the Ranchers, another Trainer class that shares the same encounter theme in those games.

X/Y

• There is a ghost girl on the second floor of the building in the Lumiose City. Junichi Masuda claims this was never coded into the game.

Sun and Moon/Ultra Sun and Ultra Moon

• Inside the player character's room, there is a signed picture of the Thunder Badge.
  • There is also a Nintendo Switch inside of the player characters room.
    • Similarly, all of the previous consoles before the Switch are inside the Shady House.
• Occasionally, a Delibird will appear from the chimney inside the Shady House.
• Inside the Akala Island City Hall, two people are talking about the GS Ball.
• Inside the Akala Island City Hall, there is a woman who greets the player character in a different language and then states the names of Stufful and Rockruff in the language she introduced herself in (For example, the lady may introduce herself with "Bonjour" and will go on to talk about "Nounourson" and "Rocabot").
• If the player character brings a Pokémon from Gold & Silver to USUM and shows it the Game Freak, Morimoto will explain how, in the past, the development team had trouble making Gold & Silver, but eventually got the help of Satoru Iwata. Morimoto then explains that he went on to start a big company, referencing how Satoru went on to become the lead director of Nintendo.
• Inside of the Pokémon Trainer School, there is an interactive book inside called "The Three Little Trial-Goers". The book features three Pokémon; a Pikachu, a Slowpoke and a Pyukumuku. Inside said book, you can choose the ending of how the three Pokémon go on their trial. In one of the endings, the three Pokémon set off on their trial. This book may seem unnecessary, but these three Pokémon can be seen throughout the game. The first time you see them outside of the book, they can be seen in Pikachu Valley, up on a hill. However, these three Pokémon sadly come to a stop when all three of them can be seen inside of Lusamine's frozen trophy room, all clustered in their own group.
• There is a side-quest where you can reunite two lost Pyukumuku named Mukeo & Mukiet, a reference to Romeo & Juliet.
• There is another side-quest where you can find a message in a bottle that can be found on Ula'ula Beach, and this can be delivered to an Ace Trainer in Malie City. When you give him the bottle, he says "Th-this... this is a letter from Arabella! He's challenging me to a battle?!". Arabella is an actual Ace Trainer from HGSS.
• If the player character repeatedly tries to walk into the trailer in Pikachu Valley, eventually, a Mimikyu will come out of the door instead of a Pikachu.
• The theme for the Ultra Wilds is a reversed remix of the opening theme that plays during the "Welcome To The World Of Pokémon" cutscene.

Let's Go, Pikachu! and Let's Go, Eevee!

• In Vermilion City, there is a trainer with a Farfetch'd named DUX. This a reference to Red & Blue where you could trade with the same trainer for the same Farfetch'd if you could hand over a Spearow. However, the trainer isn't a trade NPC and instead says he is going out with his Fafetch'd to catch a Spearow himself.
• After defeating Lt. Surge's Gym, he gives you his autograph on the Thunder Badge. This matches up with the Easter Egg in Ultra Sun & Moon where this same badge appears with an autograph, possibly meaning that Ultra Sun & Moon take place after Let's Go Pikachu and Eevee in a timeline.
• In the Pokémon Mansion, if the player character takes Mewtwo or Mew to the splicing machine on the bottom floor, they will stare at the machine. This doesn't happen with any other Pokémon other than these Mewtwo and Mew.
• A group of three Psychic Trainers that appear in Lavender Town are named Arin, Danny, and Ross. This is most likely a reference to the members of the YouTube channel Game Grumps.
• The Celadon Game Corner references past Pokémon games in the arcade machines. For instance, when observing one of the machines, there is text reading "It's a Pokémon fighting game! Is Pikachu fighting in a mask?!". This is a reference to Pokkén Tournament DX, another Pokémon-related game for the Nintendo Switch.
• In the Game Freak office buildings, there are posters for the original Red, Green, Blue & Yellow games.
• The music that plays during certain communication events (connecting the PokéBall Plus, trading, connecting online, etc.) is a remix of the PokéWalker theme.

Other games

• In Pokémon Stadium, if the player character transfers a Pokémon from Red & Blue to these games with a specific nickname, the Pokémon transferred will have alternate colors (For example, if the player character transfers a Geodude named DIG, then the Geodude will have a slight turquoise hint to it).
• In Super Smash Bros. Brawl, if the player character adjusts their camera when the Pokémon Stadium 2 stage is in Ice Mode, they will find a picture of a real cat inside of a tiny house. However, this cat doesn't seem to have any significance to anything; Masahiro Sakurai even stated that it is not his.