Mot

Mot was a  Goa'uld who once served as an  Underlord to  Ba'al until he was killed.

Background information
He fought against Ba'al and was defeated some time in Earth's past, then went on to serve him as an underlord. For some time he, like Astarte, was unquestionably loyal to Ba'al and served as the military commander for his master's Jaffa legions who were situated on the frontier of Ba'al's domain. As the god of death, the opposite of Ba'al, he set himself up as a fiend in his subject's eyes so that Ba'al, or indeed any of his underlords, could act as a hero when they cast the "dark" god out.

2003
He ruled over  P4S-237 for a hundred years after  Ba'al abandoned it, keeping the  Naquadah mining operation there from his master and taking the spoils as his own. He planned to overthrow Ba'al and take his place as System Lord. The opportunity came to him when Ba'al failed to eliminate Lord Yu in a battle that was to be a final blow against him. Yu escaped and inflicted heavy casualties on Ba'al's forces. His failure caused him to greatly lose favor in the eyes of his master, Anubis. SG-1 discovered him on the  planet and soon learned of his mining operation, threatening to inform Ba'al of it. Mot ignored these threats, however, and instead threatened to execute several of the inhabitants of the planet. In addition to this, he set in motion a plan to attack  Earth which almost led to the destruction of  Stargate Command before it could be stopped. Mot planned to kill Ba'al, gain the iris code from SG-1 and destroy the SGC to gain Anubis's favor. Mot was killed, however, when he was shot by  Natania; a local villager. ( SG1: " Prophecy")