I just solved Yoshi having kids as a male. A male Yoshi and female Birdo mate and Birdo develops an egg and it rolls out of the snoz tube thingy. Yoshi catches it with its tongue and holds it in its giant hollow nose for 9 months. A baby Yosho is made. Sometimes though, it builds up kinetic energy through anger and hatred of Mario for punching him while pregnant and the baby becomes a star child. That’s right, contrary to popular belief, Kamek has nothing to do with it. It’s just the koopa priest that blesses the Fetus Yoshi.