Yoshi is a green dinosaur that is famous for his role in the Super Mario series. His first appearance was in Super Mario World on the SNES. Yoshi is also a regular appearance in Nintendo's broad spectrum games, such as sporting titles and the Super Smash Bros. franchise.
Yoshi is perhaps best known for his ability to eat almost anything, grasping enemies with his long tongue and swallowing them. Yoshi turns foreign objects into eggs, which he can use later as projectiles by throwing them at his target.
Yoshi has appeared in a variety of colors, including the prominent colored inhabitants known as Red Yoshi, Blue Yoshi, Yellow Yoshi, Pink Yoshi, and Green Yoshi and in most games these colors come with a power variance of some kind such as a longer tongue or higher jumping, etc.
Most well known for his ability to eat enemies, different colored Yoshis do have a variety of abilities.
In Super Mario World, there are three notable Yoshis found within the world. Blue Yoshis are capable of flight. Yellow Yoshis are natural at stomping out the lights from ordinary enemies. When using the Red Yoshis, they are able of spewing fireballs for miles to come.
Yoshi's personality in the games and other media that Yoshi has appeared in has always been a friendly, willing to help personality. Yoshi always wants to help Mario, for various reasons depending on the game or other media.
In addition, Yoshi (the character) is seen more as a leader among other Yoshis, and is generally seen as "the leader" of the Yoshis in most of the games (despite having no formal leadership position, other Yoshis follow him).
Yoshi also rarely speaks. Most of the time Yoshi only communicates by saying " Yoshi!," or some variation of that. In some of the games, Yoshi makes other gibberish noises, says colors, or (in a few games) Yoshi says the word " Nintendo".
In a few games, Yoshi has actually spoken. In Paper Mario games, Yoshi has spoken, as well as the Mario & Luigi series. In a few Mario sports games, Yoshi does say phrases as well. In Super Mario RPG, Yoshi is the only one of his kind that can actually speak to Mario, so Yoshi helps to translate the other Yoshis' language for Mario. In the cartoon, Yoshi does speak, but acts much younger.
Naturally, as a playable character in the Super Smash Bros. series, Yoshi does have a variety of other abilities at his disposal. In all three games, Yoshi's signature move is to eat enemies and then lay an egg with them in it. It takes a few seconds for them to escape, making it a good strategy to try and lay an egg off the edge of the stage.
Yoshi can also go into an egg himself (in the latter two Super Smash Bros. games), and then roll back and forth, damaging whoever gets in his way. Another egg based move is throwing eggs, an ability which does minimal damage, but can be preformed quickly and repeatedly. Yoshi's Ground Pound (also known as the Yoshi Bomb) is a quick ground pound that launches nearby enemies backwards.
In Super Smash Bros. Brawl, Yoshi's Final Smash is the Super Dragon, which gives him wings, invincibility, and the ability to throw fireballs.
In the many Mario Sports games that Yoshi is a playable character in, Yoshi is usually a speed type character, lending to the fact that he is a fast runner. This is reinforced in Super Mario RPG, where Yoshis are always holding races. As part of the game's story, Mario rides on one of the Yoshis to beat Boshi (a popular blue Yoshi in the game) to progress with the story.
Some of Yoshi's other abilities include transformations, which are mostly featured in the platforming games. Most prominently in Yoshi's Island games, these transformations can change Yoshi's appearance to simulate helicopters, submarines, cars, trains, and even a digging "mole tank."
More minor transformations are the winged Yoshi in Super Mario World, and Mega Yoshi in Super Mario 64 DS.
Super Mario World series
Super Mario World
Yoshi's first appearance was in Super Mario World. Bowser had encased Yoshi (and all of his fellow Yoshis) into eggs. Mario could then free Yoshi and use him to eat enemies, jump higher, and go faster.
Super Mario World 2
Due to Yoshi's popularity, he appeared in a sequel to Super Mario World, Super Mario World 2: Yoshi's Island. The game took place on Yoshi's Island, where Yoshi had to protect Baby Mario from the Magikoopa called Kamek.
Since then, Yoshi has starred in many other platforming games, including Yoshi's Story on the Nintendo 64, Yoshi Topsy-Turvy for the Game Boy Advance, Yoshi Touch & Go for the Nintendo DS, and Yoshi's Island DS (also for the DS).
These games have all had a particular feature, Topsy-Turvy and Touch & Go's being the most unique. Topsy-Turvy has a built in motion sensor in the cartridge that allows players to "rotate" the world, and Touch & Go allows players to "draw" paths for Yoshi, but forfeits control over the actual character.
Naturally, Yoshi has made many, many more appearances in the many Mario games over the years. Three other starring roles for Yoshi have been more puzzle-centric fare.
Yoshi (for the NES and Game Boy) was a puzzle game that had players stacking various monsters from the Mario franchise, and attempting to stack together two egg fragments (thus eliminating the monsters below the hatched Yoshi).
Yoshi's Cookie (for the NES, SNES, and Game Boy) was another puzzle game in which players had to line up matching cookies for Yoshi to eat.
Yoshi's Safari was a unique game released on the SNES that took full advantage of the Super Scope. It was a rail shooter with Mario riding Yoshi and fighting various monsters from the Mario franchise.
Super Mario 64 series
In Super Mario 64, Yoshi appeared as a hidden character, but it was not until Super Mario 64 DS that he was made a full playable character.
Super Mario Sunshine series
In Super Mario Sunshine, Yoshi was also available to ride. He was also crucial in finding several of the Shine Sprites hidden in the game. Depending on what fruit he eats, he can change colors.
Super Mario Galaxy series
Yoshi made no appearance in Super Mario Galaxy but in the Super Mario Galaxy 2 trailer, Mario is seen riding on Yoshi. Yoshi does indeed make an appearance on several levels of Super Mario Galaxy 2 being a major new gameplay component.
New Super Mario Bros. series
There is also an appearance in New Super Mario Bros. Wii, Yoshi did not feature in the previous New Super Mario Bros. offering.
Other Video Game Appearances
The many spin-off games that the Mario series have seen also have Yoshi as a playable character in many of them.
Mario Kart series
Yoshi has been a playable character in every Mario Kart game thus far, and in Mario Kart: Double Dash!! he drove where he had been linked to drive with Birdo.
Yoshi appears in Mario Sports game including, Mario & Sonic at the Olympic Games (as well as the Olympic Winter Games and the London 2012 Olympic Games), Mario Golf, Mario Tennis (as well as Mario's Tennis), Mario Hoops 3-on-3, Mario Sports Mix, Mario Superstar Baseball (and Super Mario Sluggers), and the Mario Strikers series.
Mario & Luigi series
In Mario & Luigi: Superstar Saga, there was a movie theater built specifically for Yoshis, and in the sequel (Mario & Luigi: Partners in Time), the Mario brothers make a visit to Yoshi's Island.
Paper Mario series
In Paper Mario: The Thousand-Year Door, Yoshi is a partner to Mario (and he also has minor roles in the other two Paper Mario games).
Super Smash Bros. series
Yoshi has proliferate appearance in all three Super Smash Bros. games, where he has always been a playable character in the starting roster.
Yoshi has also been in every Mario Party game, Mario is Missing!, Super Mario RPG: Legend of the Seven Stars (along with Boshi).
The animated series for Super Mario World featured Yoshi as one of the main supporting characters (where he was voiced by Andrew Sabiston). The version of Yoshi in this cartoon was a much more childish version of Yoshi, acting like a very young human child. Thus, Yoshi is afraid of many things, speaks in third person, and reacts as a young child would.
Yoshi also appeared in the Nintendo Adventure Books and the Super Mario Adventures comics that were featured in Nintendo Power. Yoshi does make a small appearance in the Super Mario Bros. movie as well, looking like a small dinosaur.
Yoshi is currently voiced by Kazumi Totaka, who also composed the music for Yoshi's Story.