Tethered

The Tethered are an antagonistic race of clones in Jordan Peele's psychological horror film Us.

History
The Tethered were the result of a government experiment to control the people above ground. While the cloning of a human being was successful, according to the real Adelaide, it failed because the scientists couldn't replicate the soul. Afterwards, the program was abandoned, leaving the Tethered to perform actions of their real counterparts in crude ways. They also had to survive by consuming raw rabbits as their main food source.

In 1986, Adelaide and her parents take a vacation to Santa Cruz to the carnival. After her parents got into a verbal fight, Adelaide wanders off and discovers a hall of measures attraction. When the lights are knocked out because of the storm, Adelaide gets lost in the hall of mirrors and saw what she thought was a reflection of herself. However, the reflection was turned in the opposite direction. Realizing that the girl in the reflection was not her, the other version of her attacks and strangles her unconscious and takes her down into the abandoned facility, stole her Thriller shirt, and chained her to one of the beds.

The Tethered version of Adelaide went on to have a happy, stable life while the real Adelaide was made to suffer for thirty odd years in the Tethered society. When the Tethered took note of her being different from them, Adelaide became the de facto leader of the Tethered, and she formulates a revenge scheme where she would lead the Tethered on a mission of killing their counterparts and taking their place.

Shortly after the Tethered Adelaide and her family arrive to Santa Cruz, the real Adelaide sets the attack and nearly every denizen of the town is slaughtered in mass. Adelaide and her Tethered family invade the Wilson home and Adelaide appoints her family to separate the family members while she dealt with her Tethered self. Managing to kill all of their Tethered counterparts as well as the Tethered versions of their neighbors', the Wilson family try to escape the town only to see that the Tethered had formed a long line, holding hands in reference to the "We Are the World" campaign from 1986. After Jason tricks his Tethered Pluto into walking into the flames of a burning car, Adelaide kidnaps him, compelling her Tethered version to race after her. Killing her real counterpart, Adelaide retrieves her son and escapes the town making Jason the only one who has some awareness of her true nature.