Background character
Background characters are cameo characters that appear in a stage that correspond to their home universe (e.g. King Dedede appears in the Super Smash Bros. stage Dream Land). Note that background characters should not be confused with stage hazards (though they sometimes play that role).
In Super Smash Bros.
Peach's Castle
Lakitu can sometimes be seen flying in the background.
Congo Jungle
Necky appears flying in the background.
Dream Land
King Dedede and Bronto Burt appear flying in the background.
Mushroom Kingdom
Many classic enemies from Super Mario Bros. are seen in the background.
Planet Zebes
Ridley and Waver sprites ripped directly from Super Metroid can be seen flying around.
Saffron City
Several flying-type Pokémon, including but not limited to Pidgey, Fearow, Moltres (rarely), and Butterfree, fly across the skyline.
Yoshi's Island (SSB)
- Propeller Shy Guys appear in the background.
- A Goonie, in its Yoshi's Story design, occasionally flies in the background.
In Super Smash Bros. Melee
Brinstar
- A Chozo Statue on the main platform comes to life and briefly walks before settling down into its original position. It does not move in Super Smash Bros. for Nintendo 3DS.
- There is a large brain-like organism in the far background that shakes constantly, though it is not based upon any specific creature from the Metroid series.
Fourside
Porky Minch indirectly appears in his helicopter.
Great Bay
After three minutes have passed, the Four Giants appear on the hillside to push the falling Moon back into the sky (This is in reference to the fact that Link had three days to wake said giants and prevent the Moon from falling).
Jungle Japes
Cranky Kong is seen walking back and forth in his cottage, sometimes also rocking in his chair at some points. Flocks of Neckies can also seen in the far background.
Yoshi's Island
A Fishin' Lakitu and a Banzai Bill fly around in the background.
Yoshi's Story
Pak E. Derm can be seen walking behind the scenery.
In Super Smash Bros. Brawl
Regardless of stage and game mode, using Pokémon Trainer will have the Trainer himself stand on a platform in the background. As with the previous games, there are stage-specific background characters as well.
75m
The original Donkey Kong appears on the top of the stage, as in the original game.
Distant Planet
A Red Bulborb occasionally appears in the background. A similar Bulborb also serves as an extra platform or hazard.
Frigate Orpheon
The Parasite Queen, the first boss of Metroid Prime, appears in the background in Frigate Orpheon.
Green Hill Zone
Tails, Knuckles, and Silver can be seen running up and down the shuttle loop.
Luigi's Mansion
Boos briefly appear from the rubble of the mansion when it collapses.
Pokémon Stadium 2
Electivire, Magnezone, Snorunt, Snover, Drifloon, Hoppip, Skarmory, Cubone, and Dugtrio all appear in the background of the various elemental transformations of the stage.
Shadow Moses Island
Occasionally, Metal Gear REX, Metal Gear RAY, or two GEKKO appear in the background of the stage.
Smashville
Villagers from Animal Crossing appear in the background, depending on actual time of day and date, including K.K. Slider, Tom Nook, and others.
Spear Pillar
Uxie, Azelf, and Mesprit may occasionally appear on the stage at random.
Yoshi's Island (SSBB)
For a third time, Shy Guys appear in the background, with Support Ghosts, Chain Chomps and Goonies also occasionally appearing.
In Super Smash Bros. 4
Spirit Train
- Toon Link, in his Spirit Tracks incarnation, appears as a background character in the Spirit Train stage, where he drives the train.
- When playing the stage as Toon Link or Link, then Alfonzo will drive the train.
Pilotwings
Miis appear on this stage, flying through the sky riding jetpacks.
Find Mii
A Mii appears in the cage in the background, like the player's Mii in the original game Find Mii.
Tomodachi Life
Miis appear in the background hanging out in the apartments.
Living Room
A few Nintendogs or a cat can appear as background characters in this stage.
Tortimer Island
Kapp'n appears ocasionally in his boat. Also, Leila, Leilani, or Tortimer can appear beside the shop depending on the variant.
Reset Bomb Forest
Prior to the Reset Bomb's landfall, Viridi appears for a moment.
Prism Tower
- Multiple Magnemite appear behind the tower.
- Zapdos, Emolga and Yveltal occasionally appear flying around the tower.
- Helioptile sometimes appears in the bushes on the ground.
Unova Pokémon League
Occasionally, a Milotic, a Shaymin, or a Whimsicott will appear in place of Reshiram or Zekrom.
Skyloft
Loftwings can be seen flying around.
Wii Fit Studio
The living Wii Balance Board that is seen upon starting up Wii Fit is seen in the gym.
Mario Galaxy
Lubba, along with several other Lumas, appears on Starship Mario in the background.
Town and City
- Gracie, Dr. Shrunk, Lloid, and Redd can be seen in the City variation.
- Wendell, Pelly, and Sahara can be seen in the village variation.
Kalos Pokémon League
- Various Dragon-type Pokémon can appear in the background in the Dragonmark Chamber, including Garchomp, Hydreigon, Axew, and Dragonite.
- In the Flood Chamber, Water types Piplup, Wailord, Blastoise, and Clawitzer appear.
- In the Ironworks Chamber, Steel types Klinklang, Steelix, Scizor, and Honedge appear.
- Finally, in the Blazing Chamber, Fire types Infernape, Tepig, Blaziken, and Pyroar appear.
Midgar
Odin, Ifrit, Bahamut ZERO, Leviathan, and Ramuh appear in the background; however, they only appear when summoned and they use moves that affect the stage, such as electrifying the platforms.
Mute City (Ω form)
Captain Falcon can be seen riding the Blue Falcon in the background.
In Super Smash Bros. Ultimate
New Donk City Hall
The members of The Super Mario Players, including Pauline, appear on floating platforms, and on the ground in front of City Hall. Interacting with the band members causes them to begin performing "Jump Up, Super Star!". Captain Toad and the Odyssey can be seen in the background as well.
Great Plateau Tower
The Old Man from The Legend of Zelda: Breath of the Wild periodically floats onto the stage on his Paraglider.
Moray Towers
Judd and Li'l Judd appear on the stage, indicating who is in the lead by holding up a flag that corresponds to the player's color.
Dracula's Castle
Shadows of Dracula and Kid Dracula appear occasionally, illuminated by flashes of lightning. Other enemies make an appearance, each with an entrance based on how they appeared during their original boss battle in the Castlevania series: the Creature with Flea Man, Mummy, Medusa, Werewolf, Carmilla, and Death.
