Taymon was a humanoid man.
He claimed to have joined his civilisation's merchant fleet because he wanted to explore every quarter of the galaxy. At some point before 2373 he was infected with a Taresian retrovirus that transformed him into a male Taresian.
He "returned" to the Taresian homeworld, where he was married to three of its woman, who on their honeymoon killed him for his genetic material. This was the way the Taresians propagated their species. (VOY: "Favorite Son")