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.

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.

King Dedede as a background character in Dream Land

Mushroom Kingdom

• Many classic enemies from Super Mario Bros. are seen in the background.

Planet Zebes

• Several enemy sprites ripped directly from Super Metroid, including Ridley, 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)

• 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.
• There is a large organism in the far background that shakes constantly, and is heavily speculated to be Mother Brain, though this organism lacks the characteristic features of Mother Brain herself, such as the one eye and spikes.

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 Fishing 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.

75 m

• 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.
  File:Greenhillzone3.jpg

  Tails, Silver, and Knuckles.

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 Villager, 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 the Spirit Train stage.

• 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, 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

• Zapdos occasionally appears flying around the tower.
• Yveltal also appears.

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.