Dragon Ball Z who is broly?

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.