Tal (symbiont)
Tal was a Trill symbiont who was alive in the 32nd century. By 3189, Tal had taken seven hosts, with the latest being a Human, Adira. Four of Tal's hosts had been Starfleet officers, with Adira being given a Starfleet commission in 3189.

Tal was transplanted from its fifth host, Starfleet Admiral Senna, to Gray aboard a generation ship that was outbound from Earth in 3187. Just days after joining with Gray, Tal was forced to be transplanted to Adira when an asteroid impacted the generation ship, causing fatal injuries to Gray. ()

After Adira properly completed the joining, Gray's consciousness began appearing to them as a separate entity. After an elaborate holoprogram briefly allowed Gray to manifest in the form of a Vulcan, he stated that he and Tal were both "stuck." ()

Gray's consciousness was later unjoined from Tal and transferred into a synthetic body, resurrecting him. When Guardian Xi asked if Tal gave his consent to the procedure, Adira confirmed that Tal did. ()

Trill symbionts