Red Egg

A Red Egg is a type of Yoshi's Egg first found in Super Mario World 2: Yoshi's Island.

Yoshi's Island series
Red Eggs appear as throwable objects in Super Mario World 2: Yoshi's Island (and its reissue), Yoshi's Island DS, and Yoshi's New Island. If a Green Egg recoils two times off a wall, it turns into a Red Egg, which a Yoshi can catch and add to his stash of eggs. However, if the egg recoils too much, it falls offscreen. Red Eggs can also be obtained from red-spotted Egg Blocks, though unlike with a green-spotted Egg Block, a Yoshi gets only one egg. When Red Eggs hit an enemy, two stars appear where the impact was.

Yoshi's Crafted World
Red Eggs return in Yoshi's Crafted World, where they are once again created by a Green Egg hitting a wall twice before being recollected or hitting an enemy. They give three Hearts to Yoshi when used to defeat an enemy, with the Hearts automatically being collected upon spawning, unlike in prior games where the stars had to be manually grabbed.