Stargate: Every System Lord Ranked Worst To Best
20. Thoth
Thoth had a long history in the pantheon of System Lords. He was originally one of three 'underlords' under Apep, along with Ra and Nut. Although he had the title of 'underlord' this was the equivalent of a System Lord in the days of SG-1. He allied himself with Anubis after Anubis killed Apep, joining him in the century long war against Ra.
With Anubis defeated, Thoth went into exile with him, losing his titles as he went. He then devoted himself to scientific research, developing the first version of the Sarcophagus. The first version was rudimentary at best, causing damage to Goa'uld Symbionts and was responsible for introducing naquadah to the biology of the Goa'uld.
When Anubis returned to the Milky Way galaxy, Thoth was tasked with the development and management of the Kull Warriors. He was still working on finding the fatal flaw in the Symbionts of these warriors when he was killed by SG-1.