Odo

Odo, a shape-shifting Changeling from the Gamma Quadrant, served as the chief of security aboard Terok Nor to 2365 to 2369 and continued in that position when the starbase was taken over by the United Federation of Planets and renamed Deep Space 9 until 2375.

Early Life
Odo was one of one hundred unformed, or 'infant', Changelings sent out to explore the Milky Way Galaxy by the shape-shifting Founders of the Dominion, with a compulsion to return home later in life.

The Founders would originally claim that this was to gather knowledge of the rest of the galaxy by absorbing the experiences of The Hundred upon their return. It was later discovered the Hundred were, in fact, bait to lure the being known as the Progenitor, the entity that created the Great Link en masse and then left for parts unknown, to return. The Founders considered the Progenitor to be the one true God of the galaxy.

Odo was found in 2345 in his gelatinous state in the Denorios Belt by Cardassian scoutship Kevalu under the command of Dalin Malyn Ocett. He was brought to the Cardassian occupied planet of Bajor, where by 2353, he was being studied and later tutored by Dr. Mora Pol at the Bajoran Science Institute. 

Odo was originally simply called odo'ital, before it was discovered that Odo was actually a sentient being. The Bajoran scientists labelled the gelatinous mass (in Bajoran) as "unknown sample." The Cardassians subsequently translated this somewhat inaccurately as odo'ital, which translates from Cardassian directly as "nothing." Later on, Bajoran scientists studying Odo would change his name to a more formal Bajoran name, Odo Ital, eventually shortened it to simply "Odo". (Thus, Odo is his surname and Ital would be his first name.) Odo once dryly remarked that his name sounded like someone with a bad cold saying the words "Oh, no!" 

Terok Nor
Odo was recruited by Gul Skrain Dukat, the Cardassian Prefect of Bajor, to serve as the stations Chief of security in the year 2365. He would serve in the position past the Cardassian withdrawal and well into the tenure of Starfleet, until the end of the Dominion War in 2375.

Soon after becoming station Chief of security, he was given the nickname of 'Constable' by Bajoran freedom fighter Kira Nerys.

One of the first Bajoran deputies taken on by Odo was a Bajoran man named Shul Torem. Shul would serve on the stations security force for over ten years. 

Odo was security chief when the station was quarantined after being infected by a variation of the deadly Double Helix virus. 

2369
After the Cardassian withdrawal in 2369, the Bajoran Provisional Government requested relief efforts from the United Federation of Planets, and gave occupancy of the station to Starfleet, who rechristened it Deep Space 9.

At first, Odo didn't think he was going to like the station's new commanding officer, Commander Benjamin Sisko, but after seeing how Sisko handled Odo's nemesis, the Ferengi bartender Quark, Odo warmed up to him. 

Odo first met a being like himself several weeks after the arrival of Starfleet when the gelatinous shape-shifting serial killer Meta stalked DS9.

Odo and Meta fought outside the station and drifted through space towards the Bajoran wormhole, which was undergoing violent subspace compression, destroying anything that entered. The Ops crew managed to beam Odo back to the station, but Meta was drawn into the wormhole and destroyed. 


 * It is unknown whether Meta was an insane Founder, a member of the Hundred, a member of another link spawned by the Progenitor, or something else entirely. The Changeling credo that no Changeling shall harm another is intact as Meta essentially caused his own demise.

2370
In 2370, Quark hosted The First Annual Deep Space Nine Poker Tournament at the station. Odo played in the tournament, and managed to win the tournament after defeating Grand Nagus Zek. To Quark's subsequent horror, Odo donated his winnings from the game to charity. Odo took particular pleasure in informing Quark personally of the money's fate and witnessing his reaction. 

Following an outbreak of Bajoran flu aboard the station later that year, Odo was vaccinated along with the rest of the station personnel. However, unlike the other personnel, Odo reacted badly to the vaccination and began to experience memory loss and bouts of extreme paranoia. After being chased around the station for several hours, in which time he attacked several personnel, Odo was forced to head to the infirmary where he reverted to his gelatinous state. As he rested, Odo's memories returned and the effects of the vaccine wore off. 

Later that year a clutch of Horta eggs hatched on the station and proceed to eat it, causing chaos. In an attempt to gather the Horta Odo morphed into the form of an adult Horta (which he found extremely comfortable) and led the Horta to a set of quarters. The trick was momentarily successful until one of the Horta decided to tunnel out of the station into space and Odo was forced to form a seal over the hole to prevent the rest of the young Horta being blown out. He was transported to ops once emergency forcefields were in place. He later tried again to lure the Horta in the form of an adult but they didn't fall for his trick twice. 

2371
In 2371, Odo learned that his people were the dictatorial Founders of the Dominion when he accompanied the crew of the USS Defiant on a mission to the Gamma Quadrant. 

When the crew found themselves facing the Unclean- the race who had defeated the ancient inhabitants of the Alpha Quadrant known as the Furies-, Odo played a vital role in their defeat, travelling through the currently-unstable wormhole in a spacesuit while holding a temporally-displaced version of the Dax symbiont within him, Odo's presence allowing the crew to talk with a Jem'Hadar warrior and convince him to help them destroy a Jem'Hadar space station that had been hi-jacked by the Unclean (Time's Enemy).

2372
Odo briefly left Deep Space Nine for Betazed to witness the birth of Lwaxana Troi's son Barin; he also prevented the Tavnian ambassador Deycen from taking the newborn from Lwaxana and returning it to Tavnia. He met Deanna for the first time while on Betazed. 

Later that year, Odo assisted Starfleet in preventing an assassination of Klingon Chancellor Gowron by former Starfleet officer and Maquis Thomas Riker, who was actually a pawn of the Romulan Sela. 

2375
In 2375, Odo returned to the Great Link with the cure to a virus that was decimating the Changeling population in exchange for the Dominion's surrender in their war against the powers of the Alpha Quadrant. He left behind the woman he loved, Colonel Kira Nerys. 

The Great Link
Soon after arriving at the link, Odo confirmed that there was indeed genetic material on file for the cloned Vorta Weyoun, despite previous claims. Odo had a new Weyoun cloned to act as his personal Vorta assistant.

Three months after rejoining the Great Link, Odo assigned Taran'atar, a Jem'Hadar soldier that was not addicted to the drug Ketracel White, to travel to Deep Space 9 and act as an observer of the species of the Alpha Quadrant. Odo's hope was that the Jem'Hadar could eventually learn to be more than blood-thirsty soldiers.

Other than sending Taran'atar the Link was generally unreceptive to Odo's ideas of bring more peace to the Dominion. Odo remained an outsider and spent much of his time in solid form, receiving verbal communications from Laas when the Link made decisions. ( book two)

Soon after dispatching Taran'atar to DS9, rumors reached the Great Link of a holy woman speaking of the Prophets and of healing. The rumors also said that this woman had had contact with a mysterious race known only as the Ascendants, a dangerous race that the Link knew very little about.

Believing this woman to be the lost Bajoran Kai Opaka Sulan, Odo disguised himself as a Trelian woman named Wex and set out in search of her. Odo eventually found both Opaka, and Jake Sisko, who was on his own adventure in the Gamma Quadrant.

Opaka's knowledge of the continued existence of the Ascendants was important information for the Dominion, but Odo couldn't return to the Link without first seeing Opaka and Jake back home to Bajor.

Upon arriving back at the station, Odo quickly found himself in the middle of the Parasite crisis. Reuniting with his love Kira, Odo assisted in the liberation of the monastery at Ashalla, which was the stronghold of the alien parasites.

Odo stayed with Kira at DS9 for approximately a month, long enough to attend Bajor's admittance into the United Federation of Planets. 

The Progenitor
Odo and fellow member of the Hundred, Laas, learned the truth as to why they were sent out into the galaxy as infants at the end of the year 2376, from a Changeling that Odo named Indurane, Bajoran for 'ancient'.

Indurane explained that the Great Link and all Changelings were created en mass by a god-like being known as the Progenitor. There were no 'infant' Changelings, only Changelings that had not separated from the Link and begun to learn. This was why the Changelings had such restrictions on harming one another-- with each Changeling death, the species was brought that much closer to extinction.

The Hundred had been sent out to attract the attention of the Progenitor and lure it back to the Link so it could replenish the species.

For a brief time, it appeared as if the Changelings had succeeded and lured the Progenitor back when a nova appeared in the sky in the place where the Founders believed the Progenitor would return. But when a party of Changelings, including Odo, inspected the site, they found only the corpse of a gigantic Changeling, perhaps even the Progenitor itself, killed by the radiation of the nova.

Several days later, the Great Link dissolved as all of the Changelings that had been hoping for the Progenitor's return gave into their sorrow and floated off into space.

This left only Odo, Laas, and perhaps a few other members of the Hundred running the entirety of the Dominion. 

Over the next several years Odo concentrated on running the Dominion while Laas went off in search of other Changelings to convince them to return. Due to the structure of the Dominion in which most members never even seen a Founder the day to day operations of the Dominion were largely unaffected. During this time Odo kept the Dominion borders closed to keep the political situation stable. Odo focused his work on transforming the Dominion into a more peaceful and democratic socity. He also worked to change Vorta and Jem'hadar culture for the better, but later focused on individual members of both species, such as Weyoun and Rotan'talag - hoping that both would in turn influence others around them.

Learning of a planned attack on Deep Space Nine by the Typhon Pact, Odo boarded a Jem'Hadar ship and ordered them to take him to the wormhole. He was trapped in the Alpha Quadrant when a Romulan ship self destructed in the wormhole, causing the wormhole to close. 

Alternate timeline
In an alternate timeline in which Khan Noonien Singh was victorious in the Eugenics Wars and Humans underwent genetic engineering en masse, Odo was the bodyguard of Benjamin Sisko, the Lord-Commander of the Earthfleet and the commander of the space station D9 in orbit of Bajor. His reputation was formidable as that of Sisko. During a festival on Bajor, an attempt was made on Sisko's life. Odo saw the attempted stabbing and enveloped the would-be assassin, crushing him.