Senna Tal
Admiral Senna Tal was a 32nd century male joined-Trill Starfleet flag officer. 

Sometime around 3177, he sent out a message on an obsolete Starfleet channel calling for people who still believed in the Federation to join him on Earth. On Earth, he saw snow before he left. He died in 3187 on an outbound ship, leaving no record of the intended destination. () The Trill symbiont he carried, , survived and was implanted in Gray. ()

After Adira successfully merged with the symbiont, Senna appeared to them and Michael Burnham along with the other hosts of Tal. Senna told Adira that despite the unusual joining, Tal accepted them as it's new host. Burnham thanked Senna as his message had given her hope before he vanished. Senna's memories, now available to them, allowed Adira to figure out how to find Federation Headquarters. ()

Appendices

Appearances

Background information  
Senna Tal was portrayed by Kenneth Welsh.

Apocrypha

In the 2nd issue of Star Trek: Discovery - Adventures in the 32nd Century, Admiral Tal was the commanding officer of the Generation ship and was an unofficial Field docent/mentor to Gray Tal. The admiral learned that he was dying of a hereditary trill disease and had only a few months to live. He chose Gray to be Tal's next host.

External link

Trill
Starfleet personnel (32nd century)
Starfleet flag officers