On Route 10 in Pokémon Red & Blue, Picnicker Carol gives a description of a chunky, pink Pokémon with a floral pattern. This description perfectly matches the Pokémon Munna, from Pokémon Black & White released twelve years later.

The Sword of Justice legendaries are inspired by the Three Musketeers.
Cobalion, Terrakion, and Virizion are based on Athos, Porthos, and Aramis respectively, while Keldeo is similar to the youngest Musketeer, d'Artagnan.

There is an unused stone in the game's code called the God Stone. A gray recolor of the Light Stone/Dark Stone sprite, with the description "A phantom stone."

In the Café Warehouse in Nacrene city, by looking at middle or right tile of the door, pressing A will show a message saying: "It looks like a cabinet full of Pokémon goods."

TM67 Retaliate & TM94 Rock Smash both have a sprite oversight where the TM Sprite does not match the Type in the HUD.
Retaliate is a Normal move but is shown as a Dark Type in the Sprite.
Rock Smash is a Fighting move but is shown as a Rock Type in the Sprite.

According to the Pokedex entry for Darumaka in Pokemon White, people used to keep themselves warm by putting its droppings in their clothes.

To promote Pokémon Black and White, the Pokémon Company partnered with alternative rock band The Presidents of the United States of America to create a song titled "Can't Stop (Catchin' 'Em All)". The song mentions a multitude of Unova Pokémon alongside brief descriptors of their behavior or appearance. A music video was also created that was shared online and on a promotional DVD given out through Nintendo Power magazine. In addition to some of their original songs, the band performed "Can't Stop (Catchin' 'Em All)" live at the Pokémon Black and White launch party on March 5, 2011 at the Nintendo World store in New York City.