Baby Yoshi

Baby Yoshis are newborn Yoshis born from Yoshi Eggs, making their debut appearance in Super Mario World.

Super Mario World
In Super Mario World, red, yellow, and blue Baby Yoshis are found in Star World, where they hatch from eggs of the same color whenever Mario makes his approach. Feeding the Baby Yoshis five enemies will make them turn into adult Yoshi; however, if a baby Yoshi eats any power-up, it'll grow up instantly. Also, all the eggs Mario rescues from the Koopalings hatch into Baby Yoshis during the ending cutscene. Yoshi himself hatches directly into an adult when Mario uncovers his egg, but this is because Bowser trapped Yoshi in the egg.

New Super Mario Bros. U
Baby Yoshis have been revealed to be returning in New Super Mario Bros. U after a 21-year hiatus. They now sound as they do in Super Mario World but high pitched. They are found in color swapped Yoshi Eggs. Like in Super Mario World, they can eat enemies but they will not grow. There are three different colored Baby Yoshis. The blue ones shoot out bubbles that encase enemies and turn them into coins. The magenta ones (known as Tiny Balloon Yoshis) will inflate when the player swings the Wii Remote or Wii U GamePad, and the yellow version has the appearance of a baby Bulb Yoshi and will be able to stun enemies and will illuminate dark areas. It seems they can run away like their adult counterpart if a player carries one while coming in contact with an enemy (if hit in the back). If the Baby Yoshi hits an enemy in the front, the Baby Yoshi will eat it. When the player brings a Baby Yoshi to the Goal Pole, it will cheer and give them a 1-up. While Mario, Luigi, or the Toads are carrying a Baby Yoshi, it will vocalize with the music.

Super Mario World TV series
Baby Yoshi is the young version of Yoshi in the Super Mario World television series episode "Mama Luigi". He differs from the Baby Yoshis of the Super Mario World game, Baby Yoshi is shown to be able to move on his own and use his tongue as a baby, was able to eat many enemies without growing, and didn't possess any shoes on his feet either. He knows how to talk right from birth, but mistakes the first person he sees, Luigi, for his mother.

Tetris Attack
Baby Yoshis are known as Little Yoshis in Tetris Attack. A Yellow Little Yoshi appears in the game Tetris Attack. He appears to be Yoshi's friend. And, unlike their adult counterparts baby Yoshis have beaks.

Yoshi
Baby Yoshis appear in the game Yoshi and can be seen on the title screen. If the player puts two egg pieces together a Baby Yoshi will appear, but won't give as much points.

Yoshi's Story
The Yoshis in Yoshi's Story were newborn, however they looked different from Super Mario World's Baby Yoshis. During the story sequences at the beginning and ending of the game, they were shown to have smaller and less developed bodies in contrast to the Yoshis seen only on the very first page in the intro.

Yoshi's Island DS
A Green Baby Yoshi makes an appearance in Yoshi's Island DS. After the six original Star Children are introduced, a Baby Yoshi hatches, becoming the seventh Star Child. This Baby Yoshi is heavily implied to be the Yoshi, Mario's companion.

Super Mario RPG: Legend of the Seven Stars
In Super Mario RPG: Legend of the Seven Stars, a pudgy Baby Yoshi appears as an inhabitant of Yo'ster Isle; Mario can feed this Baby Yoshi Yoshi Cookies.

Paper Mario
A group of Yoshis children calling themselves the Fearsome 5 were encountered on Lavalava Island in Paper Mario. When they were first encountered, they were being watched over by Sushie, though they were thinking up plans of their own. When Mario later returned to the village after he discovers that the path to Mt. Lavalava is inaccessible, the older Yoshis are going berserk over the Yoshi children's sudden disappearances. Mario helped Sushie down from the tree that they trapped her in and found all five Baby Yoshis.

Paper Mario: The Thousand-Year Door
Yoshi from Paper Mario: The Thousand-Year Door is small like a Baby Yoshi, however other than being newborn he doesn't have the characteristics of the Baby Yoshis from Super Mario World as he is born with hair and is immediately able to talk after being born and even has pants. Yoshi is also able to move about in his egg.

Game & Watch series
Baby Yoshis have made frequent appearances in the Game & Watch Gallery series.

Game & Watch Gallery
In Fire, Baby Yoshi is one of three patients that need to be rescued from a burning castle. It is heavier than the Toads, however.

Game & Watch Gallery 2
Baby Yoshis appear as parachutists in Parachute. Unlike the Toads, their descent speed can heavily vary.

In Chef, Princess Peach has to feed a Yoshi, but if she feeds it overcooked food, it'll revert into a Baby Yoshi. If she feeds a Yoshi enough cooked food though, it'll release an egg, which contains a Baby Yoshi.

Game & Watch Gallery 3
In Egg, if Yoshi eats enough cookies, he'll lay an egg, which will eventually hatch into a Baby Yoshi. The Baby Yoshi assists Yoshi by temporarily eating cookies at a random angle.

Game & Watch Gallery Advance
Baby Yoshi reprises the same roles in Fire and Chef.