Marty McFly

Marty McFly was, through a variety of circumstances, his world's second time traveller and first human time traveller (the first happening to be a dog named Einstien]]. He would participate in numerous temporal displacements after his first one which occured accidentally while fleeing from irate Libyan terrorists. (Back to the Future)

Biography
Marty was born on June 9, 1968 in Hill Valley, California. Marty was the youngest son of George McFly and Lorraine Baines McFly. In the original timeline, his father was still being bullied by Biff Tannen as the latter was his supervisor at work and his mother was a borderline alcoholic due to depression.

Marty was able to change the timeline for the better, thanks to a series of misadventures in the year 1955, following his first temporal displacement. When his mother's younger self became infatuated with him, after his grandfather's younger self struck him with the family car, he and Emmett Brown masterminded a scheme to get his father and mother together. One component of this elaborate scheme was where Marty disguised himself as an extra-terrestrial named Darth Vader of planet Vulcan. He threatened to melt George's brain if he didn't ask Lorraine to the Enchantment Under the Sea Dance. After ensuring his continued existence in 1985, Marty noticed things at home changed for the better. His father was a successful author and his mother was no longer an alcoholic. (Back to the Future)

On his second temporal displacement, Marty would inadvertently create a hellish alternate reality called the Biffhorrific Hill Valley where Biff Tannen became one of the most influential men in America. This was all due to a scheme of Marty's where he intended to use Gray's Sports Almanac to earn a few bucks betting on sports events. An older version of Biff from the year 2015, steals the almanac and gives it to his younger self, who founds a financial empire based on the winnings of a wildly luck gambling streak. Marty and Doc would undo and apparently erase this hellish version of reality from existence, not knowning, however that a version of this timeline still existed in the multiverse. (Back to the Future Part II, Star Trek: Voyager - Dark Realm)

His third temporal displacement involved rescuing Doc Brown in the year 1885 after he witnessed the DeLorean time machine hit by lightning and temporally displaced. Through a series of misadventures in the Old West, Marty was able to save Doc from being murdered by Buford Tannen, an ancestor of Biff's, but was apparently unable to bring his old friend and his new beloved, Clara back to 1985. All was not lost however, as he would soon encounter them and their two sons on the Jules Verne Train. (Back to the Future Part III)

Institute of Future Technology
At some point in the 1990s, while Marty was attending college at the University of Central Florida, he would meet Doc Brown once again when the latter founded his Institute of Future Techonolgy. He would work part-time at the Institute, together with Jennifer Parker. (Back to the Future: The Ride)

In 1991, shortly after Dr. Brown's discovery of the multiverse, he would be abducted by unfriendly natives on another world he was visiting. The unfriendly natives were under the thrall of Biff Tannen, who was in turn under Armus' sway. He was able to relay this information to Brown and hide the flux capacitor before his capture. Thanks to the help of five members of an away team from the USS Voyager, he would be rescued and the flux capacitor kept out of unfriendly hands.

Marty would assist the Brown family and the Voyager away team in several battles with Biff and Armus, as well as their attendant Heartless after his rescue. (Star Trek: Voyager - Dark Realm)