Tr-8r

Origin
Tr-8r (Also known as Traitor!) is a stormtrooper from the star wars movie (The Force Awakens), he became known as tr-8r when he yelled at the protagonist of the movie Finn, and so he was known as tr-8r because it sounds similar to traitor (Tr-eight r) in the trailer of the episode 7, later in the movie he was shot and died

About
There are many ways to use this joke in the internet. The most common way is to say "TRAITOR!" when someone with a profile or a name that would suggest him supporting a point of view betrays you, and joins the other side of the argument. Another use is to take the clip of him and edit it by adding it or making it loop, or even use the voice line itself