Nirrti, a destructive goddess of darkness in Hindu reference, was a Goa'uld System Lord. Ruthless and devious, she once sent an emissary of peace to negotiate a treaty as a ploy to destroy a stargate taken by Apophis. From her underground laboratory, she had conducted experiments on the children of Hanka, hoping to create "hok'tar," an advanced human, as her next host. In order to hide her experiments, she deliberately wiped out the entire population of Hanka with a deadly bacterial infection, and created an explosive naquadah device within Cassandra, the planet's only survivor, in order to destroy Earth.
Nirrti also possessed the technology to become invisible. She was involved in the negotiations with Earth for the Protected Planets Treaty, however she opposed such a treaty, and when she used her invisibility to attack Cronus and Teal'c in an attempt to sabotage the negotiations, she was apprehended and taken into the custody of the System Lords.
After Cronus's death, Nirrti escaped custody and continued to pursue her quest for hok'tar. When Cassandra became ill from a retrovirus linked to her earlier hok'tar experiments, Nirrti was captured and detained by SG-1, but she agreed to cure Cassandra in exchange for her own freedom. She remained at large, and persona non grata among the System Lords, until arriving on P3X-367. There she continued her experiments in genetic manipulation, using a DNA resequencer on the inhabitants, including Eggar and Wodan, which resulted in psychic abilities and significant physical deformities among the population. Her genetic manipulation of Jonas eventually caused him to develop precognitive abilities as well as a life threatening brain tumor. Nirrti was killed by Wodan, who used the telekinesis she had given him to strangle her and snap her neck.
Portrayed by: Jacqueline Samuda