Isis
From The Stargate Omnipedia
The Goa'uld queen of Osiris, Isis and Osiris were imprisoned within canopic jars by Osiris' jealous brother, Seth. A millennia later these jars were discovered by an archaeological expedition (the Stuart Expedition) and eventually transported to the Americas via a transport vessel. But the ship sank en route and the jar was damaged, breaking the stasis seal and killing Isis, the symbiote, within.
Osiris' jar was preserved and he was inadverently freed by Dr. Sarah Gardner. The Isis jar was obtained by the S.G.C., where it was opened. Inside, they found the preserved symbiote of Isis.
KEY EPISODE
The Curse - Janet Fraiser and Samantha Carter examine the Isis jar, finding the dead symbiote inside.