A Yoshi Egg is an egg laid by a Yoshi. It comes in four colors: green, red, blue and yellow. The green eggs are typically found all over Dinosaur Land in ? Blocks. If Mario encounters a ? Block with a Yoshi inside, it will immediately hatch into an adult Yoshi, meaning that this is one of the Yoshis trapped by Bowser. If Yoshi is already present in the level and Mario encounters a ? Block with a Yoshi inside, a 1-Up Mushroom will appear instead of an adult Yoshi. The red, blue, and yellow eggs are only found in the Star World, where Baby Yoshis can be found and hatched. A golden Yoshi Egg can be found, along with a Koopaling, in each of the seven castles of Dinosaur Land. Once Mario defeats Bowser in Super Mario World, they march back to Yoshi's House and Yoshi's trapped friends hatch.
- Yoshi Egg (Sprite 2C)
- Red/Blue/Yellow (X&3)
- Hatches into different color (Sprite palette 02, 03, or 04) Baby Green Yoshi (Sprite 2D)
- SP3: 13
ROM Adress: xF9A2 is the sprite number that hatches when Mario does NOT have a Yoshi (default 2D)
ROM Adress: xF989 is the sprite number that hatches when Mario DOES have a Yoshi (default 78)
- If a Yoshi egg hatches into a Yoshi while there's already another Yoshi on the screen, it will turn the first Yoshi into Invisi-Yoshi.
- Pausing the game when a Yoshi egg is hatching will sometimes cause its graphics to glitch.
- Dying on the frame a Yoshi egg hatches will cause Mario's death animation to glitch a slightly, and will usually cause the shattered egg's graphics to glitch.
- If multiple eggs hatch on the same frame, the Yoshi growing animation's speed will be doubled.