Dax ( symbiont ) Dax was a Trill symbiont , a symbiotic lifeform that existed with the humanoid Trill as a joined species . Each joining of Dax with a host created a new , unique individual , but each individual also carried the memories of the previous hosts . History . As of 2375 , the Dax symbiont had been joined to nine official hosts , starting with Lela Dax in 2168 through to its latest host , Ezri . Additionally , the Dax symbiont was temporarily joined with Verad during Jadzia ' s first year on Deep Space 9 . ( ) " In an alternate timeline , Dax was later joined with Jadzia ' s descendant , Yedrin . " ( ) Dax was born on in 2018 . By 2374 , it had been married six times – twice as a groom , and four times as a bride . Dax had a total of nine children – five as a mother , and four as a father . Having been a mother three times and a father twice , Dax claimed , " " I wasn ' t very successful either way . " " ( ) Dax first served as a field docent to a Trill initiate in 2170 . Over the next two hundred years , Dax became infamous for recommending the rejection of fifty - seven candidates for joining through the program . ( ) Dax held numerous positions of distinction throughout its many lives , including head of the Trill Symbiosis Commission , the leader of the Trill government , Federation ambassador , and two careers in Starfleet . ( ) Of the Daxes , who were never that enthusiastic for garden ing , Tobin Dax was the only one who tried gardening ; however , according to Jadzia , " " he had even less luck with plant s than he did with women . " " ( ) Background information . The series bible described the Trill symbiont as resembling " a short , fat snake " . Although a Trill symbiont had appeared as early as , the producers wanted a new look for the Dax symbiont , the first such lifeform to be depicted on . " " So we streamlined it , " " said Michael Westmore , " " and made it look more like a microbe , something you ' d see under a high - powered microscope . " " Additionally , based on the idea that the symbionts were creatures that burrowed , Westmore ' s team of make - up artists made the Dax symbiont pointed at one end and added some small legs . In an attempt to give the symbiont even more realism in , Westmore inserted a vibrating pen he had found at Toys " R " Us , so the Dax symbiont could be seen moving around . ( " " , p . 87 ) Precisely how to show the Dax symbiont ( such as in " Invasive Procedures " ) was a concern for the production staff . " " We didn ' t want it to look cheesy . It was always a problem showing it , " " explained David Livingston . " " It ' s that whole idea of " Alien " ; you don ' t really want to see too much because the audience is either going to be repulsed by it or say it ' s too hokey . " " ( " Captains ' Logs Supplemental - The Unauthorized Guide to the New Trek Voyages " , p . 63 ) The British comedian Bill Bailey ( who was once a team captain on the comedy panel show " Space Cadets " , which featured shows called " Vulcan s vs . Klingon s " and " Quark s vs . Rom s " ) named his son Dax after the symbiont . He commented , " " Yes , he ' s called Dax after a symbiont , a creature that absorbs the power of others . I may just have given him too much baggage . I ' ll tell him he ' s named after the German stock exchange . " " Apocrypha . The symbiont ' s nature has saved its host ' s crewmates - and once even saved the universe - on at least two occasions in spin - off media . In the series " " , where the first four crews face a race known as the Furies who once ruled the Alpha Quadrant , a temporal disruption of the wormhole results in the " Defiant " being sent back over five thousand years into the past , with the only ' survivor ' into the present being the Dax symbiont , kept in stasis for centuries by the alternate Julian Bashir , allowing it to pass on vital information to its past self to stop the events that lead to the destruction of the " Defiant " , as well as to take control of the ' Unclean ' - a race who absorbed others into its mass , who had been responsible for the Furies leaving the Alpha Quadrant - and destroy them . During " " , when the crew were briefly trapped in Pah - wraith - inspired Hells to keep them occupied in the last dregs of real space / time existing after the destruction of the universe , Jadzia Dax was able to escape her Hell and free her friends in the same way because the Pah - Wraiths were trying to torment all seven of her past hosts and Dax itself , causing an overload of information that allowed Jadzia to work out what was happening . In the third expansion to Star Trek Online , Agents of Yesterday , a future , female host of the Dax Symbiont appears as the Captain of the Enterprise - J during the Battle of Procyon V .