The Egg is Yoshi's main weapon and is commonly found in the Yoshi series. Eggs are made by eating enemies. However, some enemies cannot be turned into eggs. Yoshi can also grab eggs from egg blocks. The Egg Throw is a primary part of the Yoshi games and must be used to complete the games. Yoshi's eggs are spotted and the color depends on the color of the Yoshi.
Yoshi Eggs first appeared in Super Mario World. Yoshis hatched from these eggs, allowing Mario and Luigi to ride on them. In Super Mario World, there were special eggs that were red, yellow, and blue. Each egg had a different talent, such as the red egg could breathe flames.
A giant egg appears in Mario Kart 64 moving by itself in a race track called Yoshi Valley and the place itself improved with more eggs in Mario Kart 8.
In both Super Mario World 2: Yoshi's Island and Yoshi's Island DS, Yoshi can eat an enemy and produce an egg or nab some from an egg block. He can only carry six eggs. They could be used to defeat enemies. In Yoshi Touch and Go, a similar effect happens. When Yoshi eats fruit, he gets an egg.
In Super Smash Bros. series
Eggs are commonly Yoshi's primary weapon. They appear in all of his special attacks, but his down special.
Yoshi's Woolly World
In this game, only the egg that is made of yarn hides your chosen Yoshi that can transform into 6 ultimate uses. If the egg bounces around and opens, Yoshi can turn into a Mershi, an umbrella, a molish digger, an airplane or a motorcycle. If the egg wiggles, grows big and also opens, he will become big as a giant. If all the levels in 6 worlds are complete, the yarn in the middle of Craft Island will make a giant rainbow egg that takes you to a super special level.