Movie 3: The Tree Of Might 

(Original Air Date: 07-07-90)

This "takes place" probably before the fight with Freeza. In the beginning, Bulma, Gohan, Krillin, and Oolong are camping. Then, the forest mysteriously catches on fire and Krillin and Gohan stop the fire, but the forest is destroyed. Then, they gather the Dragonballs and summon the dragon. They wish for the forest to be brought back to normal. Later, a group of warriors, and a saiyan, from space land and plant the Tree of Might to drain the earth's energy so they can eat the fruit from it and become very powerful. Yamcha and his friend are flying their new plane when it is destroyed from the growing of the deadly roots of the giant tree going around and wrapping itself around the earth. But, they survive somehow. All of them meet back later at Goku's place. Chi Chi demands Gohan return his new dragon friend to its home. He goes to do so and the dragon later tried to show him the tree of might.
In the house, King Kai informs Goku of the Tree of Might and its destructiveness. Goku and his friends attempt to destroy the tree and fail. A battle occurs after that with Turles, the saiyan, and his warriors. During that battle, Piccolo and Gohan show up to fight. They head off to fight in multiple areas and Turles captures Gohan and creates an artificial moon in the sky so Gohan will transform. He destroys it before he transforms and Gohan changes to a giant ape monster. Goku tries to stop this from happening and Gohan attacks Goku. Later, when Gohan nearly kills his father, his friend dragon comes and Gohan sits down and plays with it happily. Turles gets upset and hits the dragon. Enraged Gohan turns on Turles and attacks. Turles fires at Gohan, but Goku shoots of Gohan's tail just in time and Gohan lives just barely. Goku sets down his son and learns from Turles' warriors they defeated all of Goku's friends easily. Goku instantly kills them all. Then, Goku and Turles fight and Turles eats a fruit from the tree and becomes strong, nearly k.o.ing Goku. But, when Turles leaves, Goku's friends come back and fight Turles while Goku charges up a Spirit Bomb. The spirit bomb doesn't work though because there's not enough life on the earth to power it. Goku and his friends are nearly all dead, but Goku forms a massive spirit bomb from the Tree of Might's drained energy and destroys Turles and the tree.