Trash Egg, SSS Beast

This world honors those with divine beasts, ranked A to S-Tier. Black Eggs have only a 0.00000001% A-rank hatch chance, versus 30% for Golden Eggs. Ethan’s dad traded a leg for a Black Egg, but wealthy bullies tossed it into the beast waste pit. Ethan dives into the muck to retrieve it — and this worthless egg births an SSS-Tier beast.