Chao

Chao are a friendly species from the  franchise that appear in several instalments of the Mario & Sonic series, as well as making some cameo appearances in the Super Smash Bros. series. In the Mario & Sonic series, Chao usually appear in supporting roles, such as forming part of the audience and having minor roles in story modes, but in certain events appear as additional playable team members. As well as the regular form of Chao, Hero Chao and Dark Chao also appear in similar roles in the games, and the Chao-shaped robot Omochao also appears throughout the series, albeit with some slightly different roles. Cheese also occasionally appears alongside Cream in various supporting roles.

Mario & Sonic at the Olympic Games
Chao make cameo appearances in both versions of Mario & Sonic at the Olympic Games, where they appear in the audience alongside Hero Chao. Hot air balloons in the shape of Chao's heads also appear in the background of some outdoor Events, including Archery and Single Sculls in the Wii version, and Dream Long Jump and Archery in the Nintendo DS version.

Mario & Sonic at the Olympic Winter Games
Chao also make similar appearances in Mario & Sonic at the Olympic Winter Games, where they once again appear as part of the crowd, with the addition of Dark Chao, and the Chao-shaped balloons also appear in several events. In the Wii version, Chao will occasionally send the player mail. In the Nintendo DS version, Chao serve a larger role, with a pair of Chao forming part of the player's team in Curling. They carry out the sweeping role, and their color corresponds to the team that they appear on. Several different varieties of Chao, including Hero Chao and Dark Chao, also appear hosting events and setting challenges in the Adventure Tours mode, with some appearing on the unlockable photo of non-playable characters.

Mario & Sonic at the London 2012 Olympic Games
In the Wii version of Mario & Sonic at the London 2012 Olympic Games, Different types of Chao return to form part of the audience, and a Chao appears on the free sticker that can be obtained in London Party, and Cheese also appears alongside Cream to host the mode.

In the Nintendo 3DS version, Chao appear in the audience as well as the Chao-shaped hot air balloons appearing in certain events. A pair of Chao also form one of the teams that the player competes against in events that require a pair of characters to be used, though the Chao are never seen participating the events. In the story mode, a single Chao appears at the opening ceremony for the Olympic Games, and later appears in the bonus episode Junior, Super Hero?, where it is attacked by an Egg Pawn and Flapper but is saved by Bowser Jr.. Cheese also makes an appearance with Cream in the episode A Rainbow In Fog. Badges of a Chao, Hero Chao and Dark Chao can be obtained from the badge machine.

Mario & Sonic at the Sochi 2014 Olympic Winter Games
Chao appear in the audience once again in Mario & Sonic at the Sochi 2014 Olympic Winter Games, as well as the Chao-shaped balloons making a reappearance in certain events.

Mario & Sonic at the Rio 2016 Olympic Games
As well as reprising their usual role, Chao appear as referees and operating cameras in certain events in Mario & Sonic at the Rio 2016 Olympic Games, including Table Tennis and Rugby Sevens in the Wii U version and BMX and Table Tennis Plus in the Nintendo 3DS version. They also appear as additional teammates for Sonic or Mii if the opponent is Mario in Football and Football Plus in the Nintendo 3DS version.

Mario & Sonic at the Olympic Games Tokyo 2020
Once again appearing as spectators in the Tokyo 2020 events, as well as the hot air balloons appearing in the events, Chao make a minor appearance in the story mode as characters that can be spoken to by approaching them. The Chao, however, will only make comments consisting of multiple uses of the word "Chao" with no meaning. Cheese appears alongside Cream supporting characters in the events.

Super Smash Bros. Brawl
Chao make a cameo appearance in Super Smash Bros. Brawl, where a group of five of them appear as a Trophy, and another three appear as a Sticker. Cheese also appears as part of Cream's trophy and sticker.

Super Smash Bros. for Nintendo 3DS / Wii U
Trophies of a trio of Chao appear in both Super Smash Bros. for Nintendo 3DS and Super Smash Bros. for Wii U, as well as Cheese once again appearing alongside Cream on hers.

Super Smash Bros. Ultimate
A Chao spirit appears in Super Smash Bros. Ultimate, which can be enhanced into a Hero Chao, as well as Cheese appearing alongside Cream as another spirit. For the spirit battle, the player faces four Squirtle on the Windy Hill Zone that become more powerful after eating.