His backstory is: 50 years ago, with no memory of his past, he was found alone in a mysterious spacecraft that appeared in the Denorios asteroid belt.

As a result, Odo performs a uniquely important role in the ensemble: he is a character who explores and comments on Human values.

Although he doesn't know anything about his species, he is certain that justice is an integral part of their being, because the necessity for it runs through every fiber of his body – a racial memory.

[2] Co-creator of Star Trek: Deep Space Nine, Michael Piller, speaks of Odo's role within the show as being prompted by needing "a character who represented the traditions of Spock and Data, the outsider who looks in at humanity.

According to the backstory of the series, Odo was found adrift in his natural gelatinous state in the Denorios Belt in the Bajoran system.

Although his deepest desire is to rejoin the Great Link, he is reluctant to do so due to the mad crusade of the "Female Changeling / Founder" for total war against every solid in the Alpha Quadrant.

Odo is tacitly mentioned in the third season of Star Trek: Picard, set two decades after Deep Space Nine, as still being among the Great Link and having informed Worf of a rogue group of Changelings plotting a terrorist attack against the Federation.

In the initial Deep Space Nine relaunch novels, Odo is succeeded as security chief by Ro Laren, who is working for the Bajoran Militia.

[5] In the Star Trek: Deep Space Nine – Millennium series of novels, it is revealed that Odo rarely shifted into smaller forms such as insects due to a psychological block from his original training under Doctor Mora.

[6] In the Star Trek: Terok Nor novel Night of the Wolves, Odo was found in a spherical module in the Denorios Belt by the Cardassian vessel Kevalu, which was under the command of Dalin Malyn Ocett, in 2345.

[8] The character Odo, with voice acting by René Auberjonois, also appeared in the computer video games Harbinger (1996), The Fallen (2000), and Star Trek Online (2018 expansion).

[11] In 2016, Odo was ranked as the 15th most important character of Starfleet and related enlisted crews within the Star Trek science fiction universe by Wired magazine.