The Egg 1 is Yoshi's karts in Mario Kart DS. It is in the shape of an Yoshi Egg. This kart, the Standard YS, and the Cucumber are Yoshi's karts in this game. This kart is very popular in Time Trial, having great speed, great Acceleration, great Handling, perfect drift, and being light. This is a great kart for snaking, the others are the Dry Bomber and the ROB-BLS.
The Egg 1 is was to appear in Mario Kart Tour. It still exists in the game's beta, but is currently unavailable.