Dragon Ball Z who is broly?

Answer 1

Broly is the legendary super saiyan and he is also one of the enemies of Goku. As a baby Broly was senteced to death because his power was uncontrollable and so his father(Paragus) tried reasoning with King Vegeta(the one who issued the order) to make him a very useful weapon against Freiza. King Vegeta then hit Paragus with a blast and stabbed the Broly. Having left them for dead, The planet Vegeta was in the process of being destroyed but Broly harnessed his power into a bubble like form and saved his father and went to some other planet. He then grew up to become the legendary super saiyan and fight goku.

Answer 2

BRoly is not gokus brother, raditz is. Broly was born on the same day as goku and had a power level of 10,000. He was the legendery super sayan. The second super sayan ever. Broly hated goku but it is unknown why. King vegeta would not allow broly to live because he thought he was a threat (even though he was a baby). King Vegeta was going to kill broly that day but frieza destroyed the planet they lived on 'planet Vegeta'. Pegasus (Brolys father) Grabbed broly before the planet got destroyed and broly powered up and a shield was placed around them. brolys power transported them to another planet where nothing lived. Pegasus trained broly but because broly was so powerful he started to go out of control and pegasus placed a neclace or something around brolys neck which controled him. Broly grew older and one day fought goku.......The beginning of Brolys wrath! By the way the first super sayan is unknown, but vegeta mentions him in the saga where everyones fighting the Ginyu force on planet namek.

BROLY IS ALSO SAID TO BE THE STRONGEST VILLAIN EVER KNOWN ALTHOUGH SOME PEOPLE SAY BUU AND CELL IS STRONGER!