In season 2 of "Stranger Things," Eleven’s fellow test subject Number Eight is named Kali, and she leads a gang in Chicago.
Kali was taken to Hawkins Laboratory as a child and identified as test subject 008. Like Eleven, she developed supernatural abilities through Dr. Martin Brenner’s experiments, but her power is different: she can create convincing illusions that alter what other people perceive.
Kali escaped the laboratory before the massacre that killed most of the other test subjects. By the time Eleven finds her in Chicago, Kali is living with a small gang that includes Axel, Dottie, Funshine, and Mick. They target people connected to the lab and pursue revenge rather than trying to live quietly.
The character is introduced in season 2’s seventh episode, "The Lost Sister." Kali teaches Eleven to draw on anger to strengthen her abilities, but their different ideas about revenge eventually separate them. Her number is sometimes written as 008, while Kali is the name used by the character and the show.