If Mario hits certain ? blocks Yoshi will pop out.
In the Star World levels baby Yoshis are lying around in eggs. Feed them a star, mushroon, feather or fire flower or five other items that Yoshi can eat and they transform into an adult Yoshi.
Yoshi offers several advantages but also some disadvantages.
Yoshi's jump is as powerful as Mario's spin jump.
If Mario has Yoshi, can ? block or egg that would have contained Yoshi, contains a 1-up instead.
Yoshi can eat some enemies. Some of the enemies that Yoshi can eat, such as Mega Mole cannot be killed with jump. Yoshi can also eat berries and grab a power-up for Mario by eating it.
Yoshi can hold some items, such as Koopa shells, in his mouth. After some time, however, he will eat these items. Spitting out these enemies is equivalent to Mario's throwing them.
Yoshi can break yellow bricks if a large Mario (super Mario, cape Mario or Fire Mario) spin jumps and lands on Yoshi while Yoshi is standing on yellow bricks.
If Yoshi eats a red shell, he will spit it out as a flame. This flame kills the same enemies that fireballs kill, including some that jump cannot kill. Enemies killed by Yoshi's flame, except Chargin' Chucks, turn into coins.
If Yoshi eats a yellow shell, he will stomp dust when he lands. This dust kills the enemies that cape twirl kills, including some that jump cannot kill.
If Yoshi eats a blue shell, he will gain the ability to fly.
If Yoshi grabs a pair to Yoshi wings he enter a special stage (usually with out enemies - see Cheese Bridge Area for exception). When he exits this stage, the level will be completed. Yoshi wings will also transform Yoshi into blue Yoshi (see special Yoshis).
Mario and Yoshi can perform a double jump (see Moves section), allowing Mario to jump almost twice as high.
If Mario is hit while riding Yoshi, Mario will not die or shrink. Instead Yoshi will run away. Mario can recover Yoshi by jumping on him.
Fire Mario cannot shoot fireballs while riding Yoshi.
Cape Mario cannot do cape spin while riding Yoshi.
Cape Mario cannot fly as far when he has Yoshi.
Yoshi cannot climb ropes, vines or fences.
Yoshi cannot enter ghost houses or castles.
Mario with Yoshi is larger than a large Mario. This makes it difficult or impossible to reach certain areas and easier to be hit or squished.
Special Yoshis are found as babies in Star Road. Mario must feed the baby Yoshis one star, mushroom, fire flower or feather or five other items that Yoshi can eat to transform them into adult Yoshis. Special Yoshis have the same ability as normal (green) Yoshi except that:
Blue Yoshi gains the ability to fly whenever he eats a koopa shell. He is considered by far the best of the Yoshis. He is found in Star World 2.
Red Yoshi spits out every koopa shell as a flame. He is considered the worst of the Yoshis, including green Yoshi. He is found in Star World 1 and Star World 4.
Yellow Yoshi stomps dust whenever he eats a koopa shell. He is considered somewhat better than green and red Yoshi. He is found in Star World 3 and Star World 5.
