Weyoun
A man faces his clone.
A clone is an organism descended asexually from a single ancestor which is a genetic duplicate of that ancestor.
The Dominion are experts in the process of cloning which they use to create multiple copies of individual Vorta. Weyoun was cloned seven times. (Star Trek: Deep Space Nine)
In 2155, the xenophobic Terra Prime group created a binary clone of T'Pol and Charles Tucker III. She was known as Elizabeth. (ENT: "Demons", "Terra Prime")
The Romulans created a clone of Jean-Luc Picard circa 2364. He was known as Shinzon. (Star Trek: Nemesis)
In 2369, Ibudan created a clone of himself and killed it. He hoped that the lack of DNA found on the body would implicate Odo as changelings do not possess DNA. (DS9: "A Man Alone")