Broly is a fictional character in three movies of the anime Dragon Ball Z. He is a Saiyan. The name of this Saiyan is a pun of the vegetable broccoli.

As only an infant Broly had a power level of over 10,000 - compared to Son Goku's level of 2. Broly's father Paragus (a takeoff of Asparagus) became increasingly worried about Broly's inability to control his rage, so Paragus had a scientist create a necklace capable of restraining Broly. This was attached to him in his sleep for obvious reasons.

As an infant Broly became upset at Goku's constant crying (in the next pod), even though he was so much more powerful. This seemed to carry on into adulthood, as Broly's next encounter with Goku lead to him breaking the restraint of the necklace. Future Trunks, Goku, Son Gohan, Vegeta and Piccolo were unable to match Broly until they channeled all of their energy into Goku, who used the energy in one last attack which only temporarily incapacitated Broly.

After the fight with Goku, Broly (somehow) lands on Earth in pursuit of revenge. Broly slipped into a coma in the impact crater, which then filled up with water and froze over. While Broly was in the coma, Gohan grew up, Son Goten was born and Goku died. As a child, Goten was very similar in appearance to Goku (as a child), they even sound the same. By matter of chance, Goten happened to cry within hearing distance of Broly, which awoke the Saiyan due to the similarities to Goku.

Once awakened, Broly tried to seek his revenge on Goten, mistaking him for Goku. It was only after spiritual help from Goku that Gohan and Goten were able to finally kill Broly. This was achieved with a triple Kamehameha energy attack. Whle it appears that Goku was only provided moral support, the dragonballs did flash when Goten wished the dragon to help them. It's not impossible that the dragon choose to allow Goku to help, he wasn't brought back to life, just able to add his energy in. He appeared to physically be there unlike in the Cell saga when he was only a faded image. It may have allowed him to be there for that one move. We also know that Goku can come back from Other World for brief instants such as when Gohan was being attacked in the Bojack movie. However, Goku says they can beat him without his help. So it really is up to debate.

This is not the last we see of Broly. In a later movie, it is revealed that a local village Witch Doctor preserved a sample of Broly's blood, which was used to recreate Broly whole again, using bioengineering techniques. Goten and Trunks then defeated him once and for all.

Broly's transformations include Super Saiyan and his own Legendary Super Saiyan form. This is similar in appearance to an Ultra Super Saiyan 2, however, it suffers no decrease in speed. In this form he is strong enough to stand up to 4 Super Saiyans. A weak Super Saiyan and a weak Super Saiyan 2 were able to defeat him (Gohan and Goten) but they may have had help from Goku.

Broly's primary attack is dubbed Blaster Shell in the DBZ: Budokai 3 (english).