In Earth mythology, Olokun is an African deity typically associated with water. This stems from his interest in acquiring water planets and his desire to find or create a perfectly amphibious host. During the Goa'uld enslavement of Earth, he fancied himself something of a scientist, and set about trying to perform experiments on Humans in order to make an amphibious host. Despite his ego, it turned out that he really had no talent for this line of work. Undaunted, he partnered with Nirrti, who also had a desire to experiment on humans. Little did Olokun know that he was only being strung along by Nirrti, whose only desire was to further her own experiments. Eventually, Nirrti turned on Olokun and caused him to suffer such a setback that he was forced to abandon Earth altogether.
Olokun discovered an Ancient device on one of his worlds that allowed him to transport naquadah - and only naquadah - between his planets. The device only worked in vast oceans, so it was perfect for Olokun. He used it to move caches of naquadah to and fro, confusing his enemies and giving the false impression of having much more power than he really did.
The ohne Freedom Fighters are a particularly damaging thorn in Olokun's side, due to the aquatic nature of many of his planets. Although his host is currently an African human, he has attempted to take ohne hosts before. Unfortunately, their physiology doesn't sit well with him. (RPG: "Living Gods: Stargate System Lords")
Olokun was one of the System Lords who was present at the Goa'uld summit which was discussing forming a new order to fight against their mutual unknown enemy, who was later revealed to be Anubis. Olokun had lost one of his Ha'tak to Anubis when the Jaffa aboard surrendered the vessel and switched sides. Yu believed that Olokun would attempt to kill him at this meeting in spite as Yu's forces had recently defeated Olukun's. He was as surprised as the other Goa'uld when Osiris arrived and revealed himself to simply be a representative of Anubis and, despite Yu's opposing vote, agreed with the other System Lords to permit Anubis to rejoin the System Lords. (SG1: "Summit", "Last Stand")
He had sent a Jaffa by the name of Ahruk to capture the planet Oyoro for him, believing it to be a fertile planet with great resources. However, Ahruk had been met with resistance and had thus took his role on the planet much more seriously than Olokun had intended, claiming himself to be an "emperor" and wishing to unite the planet under his own rule as well as deciphering the workings of an ancient device which had once turned the planet from being fertile into its now barren form. An SG team soon arrived on the planet, however, and caused some trouble.
At some point, Olokun managed to acquire an ancient device which he was very protective of. The Ohnes managed not only to learn of this, but had in fact managed to see it. It was perhaps because of this that they started sabotaging Goa'uld crafts and technology; sabotage that was eventually discovered by an SG team. (RPG: "System Lord Plot Hooks")
Most of his fleet was wiped out in 2004 by Anubis, but Olokun was not among the casualties. However, he was killed along with Bastet when Ba'al gained control of the Kull warriors. (SG1: "Death Knell", "It's Good to Be King")