I have been thinking. What happens to mario enemies when Yoshi turns them into eggs? Well and I know that this is a long shot maybe they slowly turn into baby yoshis. Now before you say I'm crazy and call a mental hospital let's think about this when Yoshi pretty much poops enemies out they are Yoshi eggs not poo. And the eggs slowly move sometimes. Maybe that's the enemy trying to escape but is unable to because they are turning smaller. Maybe when Yoshi turns an enemy into an egg he is slowly adding a new addition to his race. What do you think of this theory?