Mini-Yoshi

The 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 new-born). His purpose in the over-world is to allow Mario to carry him and move him around much faster (like Lakilester in Paper Mario.)

While Mario, Goombella, Koops and Flurrie are fighting in Glitzville's Glitz Pit, they find a problem - One of the fighter teams, the Armored Harriers seem to be invincible to any attack they use. When Mario goes outside, he finds a Yoshi Egg bouncing around, being chased by the owner of the Hot Dog Stand. Mario catches it. The owner says he was going to use it to make hot dogs, but he lets Mario have it. After a while, it 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.

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.

As the Yoshi Kid's foster parent (of sorts), Mario names him when the Yoshi is born. This means the Yoshi Kid is the first character in the Mario RPG sub-series that could be named by the player. In the Mario series as a whole, there have been many nameable characters, starting with the main character from Mario Golf.

The color of the Yoshi Kid is determined by how long it took Mario to befriend the Yoshi after Mario finds its egg on top of the Hot Dog Stand. 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 Kid hatches, the cycle restarts.

Or, if the player enters a color for their name at the title screen, the Yoshi Kid will appear that color.

Trivia

 * In Super Paper Mario, Francis has a collection of seven Yoshi Kid dolls, each one a different color.