The Vorta are an alien race on Star Trek: Deep Space Nine.
According to the Vorta Weyoun #6, the Founders tweaked them to fit in to their plans for galactic domination. The Vorta have good hearing, bad eyesight and are immune to most poisons (possibly even Bret Michaels), although it is not clear how many of these attributes predated their introduction to the Founders.
Like the Jem'Hadar, they are cloned as needed by the Founders, although they typically reproduce in the conventional male and female fashion as well. Weyoun had at least 7 incarnations, for instance. Unlike the Jem'Hadar, they typically have a very slick, friendly, used car salesman demeanor.
Typically, the Vorta fill intermediary command positions within the Dominion. We most often see them in command of a small group of Jem'Hadar, on a planet or a ship, they are sometimes seen fulfilling other roles, like Eris, the spy in the Season 2 episode The Jem'Hadar (DS9).
They also revere the Founders as gods, although there is at least one known instance of a Vorta disobeying the Founders: Keevan, in the season 6 episode Rocks and Shoals (DS9), who sacrificed his soldiers to save his own life. The Jem'Hadar First Omet'iklan said, "We are more loyal to the Founders than the Vorta ever will be. It is the reason for our existence. It is the core of our being." The loyalty of the Vorta may be less deeply ingrained than that of the Jem'Hadar.