Replicator Carter

Samantha Carter, a human form replicator created by another replicator Fifth in the image of Samantha Carter (SG1: "New Order, Part 2"). She contacted Stargate Command saying that she was fleeing from Fifth and wanted SGC to destroy her. She betrayed both Stargate Command and Fifth and in the process she made her immune against the only threat against the replicators. She fled the Alpha Site where she was held, and then decided to acquire all technology in Goa'uld hands. (SG1: "Gemini")

What she did first was to pay a visit to the System Lords's space station and kill all of the System Lords on visit there. Amongst those who were killed by her and her bretheren were one of Baal's underlords with her Jaffa and two other Goa'uld (unknown what names) and their respective First Prime. Also killed was Lord Yu and his First Prime Oshu. (SG1: "Reckoning, Part 1")

She captured Daniel Jackson and tricked his mind into believing she was Oma Desala again offering ascension. He thereby opened his mind to her, revealing things that he wasn't aware of, including a weapon capable of killing her and the other replicators. The weapon was situated on the planet Dakara. (SG1: "Reckoning, Part 1")

She and the other replicators were later killed when that same weapon were calibrated right and activated. (SG1: "Reckoning, Part 2")