Thomas 'Tommy' Oliver (portrayed by actor Jason David Frank) is a fictional character and hero in the Power Rangers universe. He starred in the Mighty Morphin Power Rangers TV series, as well as four of its successive incarnations Mighty Morphin Alien Rangers, Power Rangers: Zeo, Power Rangers: Turbo, and Power Rangers: Dino Thunder.
Tommy is strong and loyal, and very good in martial arts as he is both a teacher and student. A common theme of the four incarnations he plays a major role of is his loyalty, often being a victim to turn him against his fellow Rangers. He is often a leader, instilling his leadership skills in both the Power Rangers he works with and the students that he teaches.
Mighty Morphin
Green Ranger
Tommy was first introduced in the Mighty Morphin' incarnation as the Green Mighty Morphin Ranger. Rita Repulsa had cast an evil spell, making Tommy obey her, granting him evil Ranger powers and weaponry, and the Dragon Power Coin. He used the Dragon Dagger to summon his zord, the mighty Dragonzord. He destroyed half of the Command Center, made the Rangers lose touch with Zordon, and their Megazord. With Zordon's help, once he had returned, the Rangers freed Tommy from Rita's control when Jason Lee Scott, the Red Ranger, destroyed his weapon, the Sword of Darkness. With the sword gone, so were his evil ranger powers. From this point on, Tommy lended his power and zord to aid the Rangers against Rita Repulsa.
As time went on, Rita cast a spell, in the form of a green candle (using her contact with the Dragon Coin as a base), to make Tommy's Green Ranger powers fail (and, by default, return back to Rita), but Zordon was able to save them by having Tommy transfer the powers to Jason. Tommy was now powerless, and the Red Mighty Morphin Ranger possessed his Dragon Dagger and Shield and control of the Dragonzord.
Tommy had returned to claim his powers when the Rangers' parents were in danger and continued his role as the Green Ranger. However, his powers were very unstable now and had to be recharged several times by Zordon. His powers were completely destroyed when Lord Zedd forced Tommy into battle with a monster called Turbanshell.
Dating Kimberly Ann Heart
He then befriended Kimberly Hart, the Pink Mighty Morphin Ranger, and started dating her.
White Ranger
Luckily, Zordon and Alpha 5 were able to create new powers, making him the White Mighty Morphin Ranger, and the new leader of the Power Rangers. He uses his enchanted talking saber, Saba, to summon the White Tigerzord. He lost those powers when Rita and Zedd destroyed the Rangers' Power Coins.
After the Thunder powers were destroyed by Rito Revolto, Tommy and the other Rangers went on a quest to find the legendary Ninjor and receive his Ninja Coins. In addition to his re-charged Morphin powers, he gained new powers as the White Ninja Ranger with the power of the Falcon and the Falcon Ninjazord. Tommy met Katherine Hillard (whom he would wind up marrying in a possible future) at a time when she was also under Rita's spell. When she stole the Falconzord and Ninjor, Tommy gained the White Shogunzord (after battling Zedd himself to rescue a kidnapped Kimberly (also Kat's work)).
Zeo
Tommy gained the powers of the Red Zeo Crystal, becoming Zeo Ranger 5 in Power Rangers: Zeo. Tommy faced a great challenge when the Zeo Zords were severely damaged and he then had to rely solely on the Red Battlezord, a machine that was telepathically controlled. Tommy had a tough time with it because it would lose control anytime he got emotional. He had to go on a spiritual quest to settle his inner demons and gain peace with himself.
In King for a Day
Tommy, at one time, was captured by Prince Gasket of the evil Machine Empire and brainwashed into attempting to destroy his friends, believing them to be the threat to the world. Luckily, they were able to save him.
In A Season to Remember
In an episode of Power Rangers: Zeo, a possible future is shown in which Tommy has wed Katherine Hillard, and the couple has children and eventually grandchildren, one of whom is a Ranger himself. However, this view of the future is seen as increasingly unlikely as Tommy had been seen after the series in question apparently single.
Turbo
With a new villain in Divatox at the onset of Power Rangers: Turbo, Tommy and his fellow Rangers abandoned their Zeo powers for the newly created Turbo powers, becoming the first Red Turbo Ranger. His tenure as the Red Turbo Ranger was a short one, as he was allowed to move on with his life after graduating from high school. Before he left the series, he had hand-picked his successor, Theodore Jay Jarvis Johnson.
For a long time, it was not explained what happened to him after he left the series, although his reappearance in Power Rangers: Dino Thunder helps to fill in some of the gaps (Some fans consider such a fill-in to be a retcon). Tommy went on to college and graduate school, gratuating with a doctorate in paleontology. During this time, he had met Hayley Viktor, and with her help he constructed the Dino Thunder powers based on parts of older Rangers' powers. He was also partners with Terrence "Smitty" Smith and Anton Mercer on a project on dinosaurs that had gone horribly wrong (the resulting explosions resulting in them becoming Zeltrax and Mesogog, villains Tommy would soon face). At the same time, he kept notes about the various teams of Power Rangers, leading to his next formal appearance in Power Rangers, in the Power Rangers: Wild Force episode "Forever Red."
Wild Force
When word of a planned invasion of Earth by resurgent Machine Empire came to Tommy from Andros, the Red Space Ranger, he recruited the nine other Red Rangers into helping him stop the threat. Although it was not explained in "Forever Red," it is generally accepted that many of the powers that were lost during the course of Power Rangers were recreated for "Forever Red" by Tommy and Hayley. Another less popular theory is that "Forever Red" is out-of-continuity with the rest of the Power Rangers saga.
Dino Thunder
After the events of "Forever Red," Tommy became a teacher, teaching science at a school in the fictional city of Reefside, California at the onset of Power Rangers: Dino Thunder. There, his past, including his tenure as a Power Ranger, is unravelled to three detention students, who become the Dino Rangers. Forced back into action by Mesogog, he became the Black Dino Ranger, aided by the power of invisibility from the Black Dino Gem. For a while, he was encased in amber by the White Drago Ranger, and once freed he was unable to demorph. He was later freed by a special ooze, only to become permanently invisible due to his inability to control the powers of his Dino Gem. When he woke up, his gem was fully repared, and he gained Super Dino Mode. His Dinozord was the Brachiozord, he welded the Brachio Staff, and he drove the Black Thunder ATV. At the end of the series, the Dino Rangers scraficed their Dino Gems (and their powers) in order to destroy Mesogog, who that point his separated from Anton Mercer. In the aftermath, Tommy decided that he would try to lay low for a while and live a normal life as a simple high school teacher.
In Fighting Spirit
Although he eventually freed himself from the invisibility, his gem shattered and he was left in a coma. During this coma he was fought by several versions of his past ranger powers in the form of the Green and White Mighty Morphin Rangers and Zeo Ranger 5, Red. After proving that he would not give up the fight for his life, he awoke from the coma, his gem was repaired, and he gained Super Dino Mode.