Information: Dragonball Z: Television Specials
Special 01 - Bardock: Father of Goku
After destroying the entire Kannassan race, Bardock (Goku's father) and his men relax and discuss various topics. However, a last surviving Kannassan manages to attack Bardock by surprise, successfully landing a blow on the back of Bardock's head. The blow has a strange result: it bestows on Bardock the ability to see the future. Seeing his planet and people killed by Frieza and believing his son will also later die, Bardock takes it upon himself to attempt to gather the Saiyans to kill the tyrant. Receiving nothing but mock and disbelief, Bardock flies to space and faces Frieza himself.
Special 02 - The Trunks Story
With Goku dead from a viral heart disease, the Z Warriors are faced with defeating Dr. Gero's androids on their own. The battles end with only Gohan surviving and years of the Earth being ravaged and destroyed by the androids since there is no one strong enough to defeat them. Angered by the destruction-taking place, Trunks asks for Gohan to train him to help with the android fight. During a battle with the androids, Gohan and Trunks are both severely beaten, and Gohan gives Trunks the last senzu to save the teenagers life. This leaves Gohan with only one arm. When the androids attack the Western Capital, Gohan dies. When finding Gohan's body, Trunks transforms. Years later, Bulma completes the time machine that she wants Trunks to travel back in time in. But, Trunks wants to take one more shot at the androids.
Special 03 - Plan to Destroy the Saiyan
While gathering firewood, Goku and Gohan notice that the trees and forest area around them are dying. Mr. Popo floats down to them and explains that a gas called Destron is destroying all life on Earth (including human), and will eradicate everything within 72 hours. They join up with Vegeta, Piccolo, and Trunks, then set out to destroy the Destron-emitting machines. Just when they believe all the machines have been destroyed, another is found. This one has a protective shield that even Goku's ki attacks can't penetrate. To save Earth, Goku, Gohan, Trunks, Vegeta, and Piccolo journey to the Dark Planet to face Dr. Raichii.