Mini-Yoshi

Yoshi (sometimes called Yoshi kid) is Mario's fourth party member in Paper Mario: The Thousand-Year Door. He's a spunky little kid and the youngest of Mario's party members (being newborn). His purpose in the overworld (outside of battle) is to allow Mario to ride him and move him around much faster and use a Flutter Jump-like ability to cross gaps (like Lakilester and Parakarry in the first Paper Mario). In battle, he starts out with Ground Pound and Gulp; once powered up, he learns Mini-Egg, and when powered up a final time, learns stampede.

Paper Mario: The Thousand-Year Door
While Mario, Goombella, Koops and Flurrie are fighting in Glitzville's Glitz Pit, they find that one of the fighter teams, the Armored Harriers, seem to be invincible to any attack they use. At an earlier time, Mario had found a Yoshi Egg bouncing around, being chased by the owner of the Hot Dog Stand (who had hopes of making a Southern Fried Egg Dog of Tastiness with it). Mario eventually caught it, and Mr. Hoggle allowed him to keep it as most people "don't like to eat things that move". After Mario returns from his problematic battle with the Armored Harriers, the egg hatches into a Yoshi kid who thanks Mario. He then joins Mario, who proceeds to name him. The Yoshi Kid can defeat the Armored Harriers by eating them and spitting them at each other. He travels with Mario for the rest of the game.

At the end of the adventure, he goes solo at the Glitz Pit, going under the name "The Great Gonzales Jr.", and is getting close to the title match. In Goombella's letter, the Yoshi challenges the "Great Gonzales" by saying "I could totally take you in the ring now, so bring it!". He is notable for calling Mario "Gonzales" throughout the entire course of Paper Mario: The Thousand-Year Door (in a manner similar to non-player characters such as Goldbob and his family); his odd familiarity with this name is due to the fact that Mario took up the pseudonym "Great Gonzales" while fighting in the Glitz Pit, where he met Mario. By the end of the game, though, Yoshi would appear to have slowly realized that "Gonzales"'s real name was Mario, but he'll always want to call him Gonzales.

Super Paper Mario
In Super Paper Mario, Yoshi appears as a Catch Card won by winning the Duel of 100 in the Sammer's Kingdom. Francis has a collection of seven Yoshi dolls, each one a different color. Lastly, Yoshi, along with all the other partners from the previous Paper Mario titles appeared in a photograph at Mario's House during the introduction.

Color
The color of Yoshi is determined by the amount of time that passes between the point where its egg joins Mario's party atop the Hot Dog Stand to when Mario eventually meets the newborn dinosaur after running from the Armored Harriers. The egg starts off with a green Yoshi Kid inside, and changes color every few minutes, as shown on the chart below. If more than twenty minutes elapse before the Yoshi hatches, the cycle restarts. The color has no effect on his power, despite popular belief.

Catch Card

 * Card Type: Rare
 * Card Description: It's Yoshi from the last Paper Mario adventure. This scrappy Yoshi was the only way to travel!
 * How to Obtain the Card: The Duel of 100 in Sammer's Kingdom needs to be completed in order to obtain all Paper Mario: The Thousand-Year Door partner cards from King Sammer.

Trivia

 * As stated above, Yoshi's Glitz Pit origins resulted in him calling Mario by the name "Gonzales" throughout the whole course of Paper Mario: The Thousand-Year Door. As a matter of fact, Yoshi only calls him "Mario" six times in the game: once at the ending of the game, once more in Grubba's office when reading his secret paper about the machine under the ring, then at Twilight Town when the steeple bell rings, changing Mayor Dour into a pig, another time at Keelhaul Key after Frankie says "I love you" 100 times, one more time at the very end of Chapter 5 when the Piantas say they're staying on Keelhaul Key, and yet again if Mario brings him along to the top of Riddle Tower for the first time. Although the use of "Mario" in the ending was deliberate and even played somewhat of a role in Yoshi's character development, the other listings were likely a mistake on the developers' part.
 * Yoshi is one of two Yoshis that can be seen outside of battle in Paper Mario: The Thousand-Year Door.

Names in Other Languages
Note that the player can, as in the English version, name this character anything. These names are given to the character if none is entered.