In the year 559, Nessie was one of the spawn born to Olokun. When Nessie and the other symbiotes came of age for hosting, Tangaroa, an Underlord of Olokun, offered host bodies of his creation and Hou Kaingans he experimented on. He gave Nessie a failed experiment body with aquatic lungs that never properly developed.
Nessie spent a little bit of time on Hou Kainga but not for long, as Olokun was very paranoid thar his children would conspire against him. Nessie was sent away from his domain and ended up at a lake in the Scottish Highlands, where he took the name Loch Ness.
Passed down through genetic memory, Nessie, like Olokun, was a scientist more interested in host biology than Goa'uld politics and ruling others. Nessie mostly spent time with aquatic creatures and tried to create aquatic hosts. He also tried to be beneficial in other ways to Olokun and Nirrti's domains by experimenting on those who he figured by what he'd read in Goa'uld reports that were deemed worthy trustable, or out of curiosity on how they would use their advancements. He saw these experiments as rewards to his parent's worshipers and loyal Jaffa. However, many of these experiments would end up failures which gave him guilt. Eventually, in a drastic action to attempt to gain more genetic engineering knowledge, he stole some DNA from Nirrti and experimented with himself with it.
When Nirrti & Olokun’s partnership ended, Loch wanted to help and was willing to try something different to do it, which had the added benefit of escaping his cycle of guilt and failures. However, given Olokun's paranoia Nessie would have to earn the right to join what would become the Cursor'va. On Gualun, Nessie was forced to kneel and tortured with Goa’uld brainwashing to see if he was a Nirrti plant. They 'trained him' to be a good servant for Olokun, and to refrain from Nirrti’s more dangerous knowledge such as contagions. He was also led to believe that he chose Olokun over Nirrti as Nessie valued trust and respect and believed Nirrti's power games had warped her values and was led into proving his loyalty to Olokun's cause, by publicly renouncing her actions and supporting him. With enough training and brainwashing, Nessie eventually was trusted enough to be put in charge of a squad of Cursor'va, Olokun's counter-intelligence agents and secret police. Loch sought out spies and traitors as well as spread chaos to enemy domains secretly through disinformation and rumors. This secretiveness and lack of knowledge about him personally left outsiders who observed the results of his labors and experiments with theories and whispers of what Goa'uld was responsible for these things. It was very rare for a Goa'uld to do things without taking credit for them and boasting about it after all, though those who cared enough about the secret, like the Tok'ra, could connect the dots.
Overtime, the system lord's fleets dwindled as half of Olokun's Jaffa ditched him for Anubis, who decimated most of those that had remained. Loch felt like Olokun's domain was screwed and just hoped maybe somehow, he could work out a deal with the Tau'ri alliance to find some sort of compromise. He figured if they joined forces against Anubis instead of trying to undermine them maybe things could change to try to be more favorable for everyone, since clearly Olokun's people weren't happy with him and Olokun wasn't happy with them either and had become paranoid of most people and wasn't able to just be a scientist like he wanted anymore either. He figured if they could start over and just try a different approach that all three Tau'ri, Jaffa, and Olokun could agree on maybe the Tau'ri wouldn't just wipe them out and also keep them from being wiped out by Anubis as well. So Olokun's domain could live on but just changed for the times and taken a different form. However, Olokun refused Loch's idea to form an alliance.
When Olokun refused, Loch didn't really think there was any other option available to them. The planets would fall and people would die for his Goa'uld pride. Believing the Goa'uld in general wouldn't actually band together and do what needed to be done to survive and win the war, Nessie formulated a plan of his own, figuring the only thing he could do was show him that it could happen that he could bring them to the table and prove that it wasn't just a stupid impossible idea. Using his intelligence agents, he gathered all information he could and had his agents bug all Tel'taks that they could to find the location of potential Tok'ra bases. After finding a world repeatedly visited with nothing of note to the Goa'uld political landscape, he deleted the location from their data. He then got caught by those Olokun used to spy on him. Olokun and his Jaffa then came to arrest him as his hoarding of data felt like proof to Olokun that he was indeed betraying him to another and disowned him and ended up putting a bounty on his head.
Nessie managed to get away, however, feeling like he had nothing left, due to the fact he couldn't return home again, and still feeling like the Tau'ri were the best bet against Anubis to destroy him before he destroyed his home, Loch traveled to the planet by himself with all the data on the Goa'uld the Cursor'va gathered and left himself defenseless and waited with hope that he'd be captured by the Tok'ra and not a rival Goa'uld. It was the Tok'ra. Loch Ness was tested carefully with the Za’Tarc detector, and his intentions were shown legit. He wished to help the Tau'ri and their alliance with the Tok'ra and other races. After passing their questions, going over the plethora of data he gave freely, and taking into account his vague notoriety, the Tok'ra slowly came around to accepting him although not without supervision for a long while.
Later he finally got a chance to help out the Tau'ri and the Phoenix Alliance directly when he was cleared to join Phoenix Site. He was given the position as leader of the misfits of Phoenix-13 and Loch Ness was ready to prove to them he could earn their trust and respect and aid the cause.