Leonard McCoy (alternate reality)

Leonard McCoy was a Starfleet doctor. As of 2258, McCoy was chief medical officer of the USS Enterprise

Family
Leonard H. McCoy, the son of David Andrew McCoy and Eleanora McCoy, was born in Atlanta, Georgia, United States of America, Earth on 20th January 2227. His grandfather, Thomas Jackson "T.J." McCoy, M.D., was the Chief of Medicine at Emory University Medical Center in Atlanta in the 2220s.

Early life
In 2231, at the age of four, Leonard accompanied his father on a trip to Aberdeen, where he briefly met young Montgomery Scott.

By 2255, McCoy was a medical doctor and was divorced from his wife. He decided to enter Starfleet Academy, and boarded a shuttlecraft at the Riverside Shipyard in Iowa, where he met James T. Kirk for the first time.

At some point McCoy had a relationship with Dr. Elizabeth Dehner which ended badly. Dehner would later cancel a transfer onto the Enterprise because she had still not forgiven McCoy.

Starfleet Academy (2255-2258)
In summer 2255, McCoy was attending Starfleet Medical College when he was swept into the search for the serial killer known as the Doctor. McCoy treated Academy Cadets Gaila and Nyota Uhura after each was attacked by the Doctor. In collaboration with several other scientists, McCoy determined that the Doctor was using a swarm of extremely powerful nanites to remove victims' internal organs without leaving incisions. McCoy, Uhura and Dr. Patricia Park discovered that the Transamerica Pyramid was the Doctor's hideout. McCoy, Kirk and Uhura headed for the skyscraper, McCoy outfitting Kirk with weapons designed to combat the nanites. Kirk and McCoy entered the building's spire and fought through the nanites to find the hooded Doctor and four similar figures, all of whom proved to be coalesced swarms of nanites. McCoy and Kirk were nearly killed, but the nanites retreated and left Earth. At this time McCoy had already formed a close friendship with Kirk, who had begun calling him "Bones".

In 2258, McCoy participated in Kirk's third Kobayashi Maru test, on which Kirk cheated in order to win. McCoy attended Kirk's disciplinary hearing, at which they both met Commander Spock for the first time. It was reported that Vulcan had sent a distress call, and many of the cadets were called into action, including McCoy, Spock, and Uhura. As he was under academic suspension, Kirk was not given an assignment, but McCoy injected him with a vaccine in order to give him the appearance of a disease and transfer him aboard the USS Enterprise under his medical care. The Enterprise reached Vulcan only to be attacked by Nero and the Narada, which had already destroyed the rest of the fleet. When Dr. Puri was killed in the Narada's initial attack, McCoy became Chief Medical Officer.

Spock took command of the Enterprise in the absence of Captain Christopher Pike and was forced to throw Kirk off the ship for insubordination, marooning him on Delta Vega. Spock acknowledged how difficult it must have been for McCoy to support him against his friend Kirk. McCoy opined that Spock was out of his mind to maroon Kirk; he was certain Kirk would triumph in the end. After Nero's defeat, McCoy was permanently assigned as chief medical officer of the Enterprise.

Aboard the Enterprise
Months after the destruction of Vulcan, the Enterprise set out on a mission to the edge of the Milky Way Galaxy. When the ship encountered the force field at the edge of the galaxy, Kirk's Academy friend Lieutenant Gary Mitchell was mutated into a superhuman being. McCoy monitored Mitchell in Sickbay as the young officer's behavior became increasingly erratic; at one point he shoved McCoy across the room when the doctor recommended that Mitchell rest. Refusing to be stranded on Delta Vega I, Mitchell blasted Kirk with energy from his hands but was knocked out by McCoy with a sedative. Kirk was subsequently forced to kill Mitchell.

For the mission to Nibiru, McCoy was in charge of the cataloging of fauna and a focus on potential pathogens.

A year later, McCoy was on Nibiru helping prevent a volcano from causing the extinction of the Nibirans, all while avoiding breaking the Prime Directive. McCoy greeted Kirk with a docile animal as their getaway transport, but Kirk accidentally stunned it, forcing them to run and jump off a cliff to dive to the Enterprise, hidden beneath the waves. On the bridge McCoy listened as Spock, who was activating a cold fusion device to stop the volcano's eruption, asked them to leave him, as getting the Enterprise in range to beam him out would expose the ship to the natives and ignore the Prime Directive. While McCoy asked Kirk to consider what Spock would do in his position, Kirk opted to rescue him and ignore the Directive anyway.

Later, Kirk was ordered to hunt down the traitor John Harrison, who was behind a bombing in London and an attack on Starfleet Headquarters that left many, including Admiral Pike, dead. McCoy expressed skepticism, believing his friend was too inexperienced to combat him. Kirk found Harrison on Qo'noS, and witnessed him taking down scores of Klingons singlehandedly, so he ordered McCoy to investigate the source of his superhuman strength. McCoy analyzed his blood, and found it possessed extraordinarily regenerative platelets, which he experimented with by injecting into a dead tribble.

In the meantime, Harrison was reticent about his motives but suggested Kirk examine the 72 experimental photon torpedoes Admiral Alexander Marcus had given them to fire on his location. McCoy was skeptical, but took a shuttle with Marcus's daughter Carol to examine one of the classified weapons on a meteor. He accidentally activated it and trapped his hand: Kirk ordered him to be beamed up, but was warned doing would also bring an exploding torpedo aboard. Fortunately, Marcus deactivated it before she could be beamed up. The two then opened up the torpedo and discovered it contained a man in cryogenic stasis.

Harrison explained he was actually Khan Noonien Singh, having been revived and forced by Admiral Marcus to design weapons and ships for a war with the Klingon Empire. He had attempted to smuggle out his fellow Augments on the torpedoes, but was forced to escape when his scheme discovered: believing Marcus killed his family, he responded in kind in London and San Francisco. Marcus appeared in the Dreadnought-class USS Vengeance and opened fire on the Enterprise when Kirk refused to hand over Khan, but its weapons were deactivated by Montgomery Scott, who boarded the ship during a leave of absence. Kirk and Khan allied to fly over and commandeer the ship, but a suspicious Spock asked McCoy to remove the cryopods from the torpedoes.

As expected, Khan took the Vengeance for himself, but McCoy removed the cryopods so Spock was able to use the torpedoes against Khan, crippling his ship. Both damaged ships began hurtling to Earth: Kirk entered the warp core to reactivate the Enterprise's engines, but did not put on a containment suit and suffered radiation poisoning. Kirk was brought to sickbay, where he lay dying as McCoy examined him. When he returned to his desk, the tribble he had inject came back to life. McCoy ordered one of the augments' cryotubes brought to sickbay. Its occupant was removed and reanimated, but McCoy ordered them maintained in a medically-induced coma. He and Marcus then placed Kirk in the cryotube, placing him in suspended animation to preserve his brain. Spock and Uhura beamed down, subduing Khan after he crashed in the Vengeance, allowing McCoy to perform a blood transfusion on Kirk.

McCoy later greeted a conscious Kirk in a hospital room as his attending physician, checking his vital signs and whether the transfusion had any psychological effects as well. In 2260, McCoy attended a memorial for the lives lost the previous year, and continued serving on the repaired Enterprise. He was less than pleased however, to learn they were embarking on a five-year mission.

Starfleet Academy indicated interest in having McCoy serve as an instructor when the assignment to the Enterprise was completed.