They're both twin Irken hybrids in a special experiment. Both are strong and dangerous. Karen has sliver hair with black tips and blue streaks, she has scars, a tattoo, a robot arm, a torn and kinked antenna, and has unusual powers. Silver has the same hair as Karen, has a kinked and curly antenna, a burnt hand, and also has powers. Both of them have a tooth sticking out. Silver is a smart, crazy Irken hybrid but, Karen is crazy, violent, and defected Irken hybrid. They are friends with all of the Irken including zim and Tak also Gaz and GIR but, Dib is their enemy. Silver likes dib and Karen is Zim’s girlfriend. They love video games, rock bands, techno, animals, and etc. They're SIR units are named foxy and batty. Both of them are rulers of animals, monsters and other life forms. Karen and Silver are masters at using any weapon. They are one of the most dangerous Irken ever. They are kinda tall and Zim’s age. They live with their best friends Nad and Kazu and are lots of fun. They were banished but zim and the gang saves all the Irken and the tallest life, so that's how zim and Tak became official invaders. Karen loves torturing dib by severely hurting him either alone or with friends but, silver loves torturing a Irken traitor named Amanda who is dib's girlfriend so they are a little bit different and they can lose control of themselves. Karen purple and black and silver wears red and black. Their eye color can change but they are mostly magenta and dark pink also they have slits for pupils. Karen became Zim’s girlfriend when they saving everyone's life she told zim that she loves him and silver likes dib because dib saved her from drowning. Silver's disguise has red eyes (lens), a hazel bandanna, wearing torn jeans, and a blue tank top with long indigo sleeves, Karen’s disguise has indigo eyes (lens), a red bandanna with gray x's, also wearing torn jeans, and a purple tank top with long black sleeves. They are fun and cool so they will be anyone friends. They both had a messed up history of power, death, violence, and missions. They almost destroyed the Resisty. When they were young tallest red and purple adopted them.
They are both in the same experiment known as Irken Special Experiment KAR3NS11V3R