buub is a monster that came from useta to fight goku and his friends but stop by new namek and new vegeta so the heros of earth knew he was on his way so they trained to beat him but he stoped by hell and absorbed cell
then when he got to earth vegeta fought him and lost
Fights
buub vs piccolo
buub vs all of the saiyans on planet vegeta
buub vs king vegeta
buub vs cell
buull vs vegeta