A hidden feature in these Pokémon games is the ability to tell a certain NPC four specific words or phrases using the easy chat system in order to unlock special rewards. Which words are required are unique per save file.
In Diamond, Pearl, and Platinum these rewards include 8 different special PC box wallpapers. The NPC to speak to is located on the 3rd floor of the Jubilife TV station.
In HeartGold and SoulSilver, rewards include 8 different PC box wallpapers plus 3 different Pokémon eggs. The NPC to speak to is located in the Violet City Pokémon Center.

The original distribution of these passwords was via the Pokémon Daisuki Club, a defunct, Japanese-exclusive official fan club website.
Below is both a calculator to generate the passwords for your specific save file, an in-depth explanation of how the password check system functions, and a full dump of the relevant word data.
: A vertical-focused mode requiring more jumping and air maneuvers.
: An unlockable mode where the bus grows automatically without needing passengers.
is an arcade-style indie game that blends the core mechanics of the classic mobile game Snake with the frantic urban driving of Crazy Taxi . Developed by the two-person team Stovetop (Frank Han and Jeff Zhu), the game challenges players to navigate various 3D environments while their vehicle grows increasingly long and unmanageable. Gameplay Mechanics Snakeybus
The primary objective in Snakeybus is to pick up passengers from designated stops and deliver them to landmarks across the map.
: To survive tight corners or avoid their own tail, players can use a jump/boost ability, drift around corners, and even hop over other segments of the bus. : A vertical-focused mode requiring more jumping and
Snakeybus is available on several platforms, including , Nintendo Switch , PlayStation 4/5 , and Xbox One/Series X|S .
: Each successful passenger drop-off causes the bus to grow in length. Developed by the two-person team Stovetop (Frank Han
: Unlike traditional driving games, your own trailing "tail" of bus segments becomes the biggest obstacle. You must avoid crashing into your own ever-growing body.