Serrakin appear to be a reptilian species, humanoid in shape but having scaled skin and reptile-like eyes. They are capable of speaking English and interbreeding with humans. Half-Serrakins possess the distinctive bone structure of regular Serrakin, but have lighter skin which does not appear to be scaled. (SG1: "Forsaken")
The Serrakin live in peace with Hebridians, who they freed from the Goa'uld thousands of years ago. Interspecies marriages are fairly common. There were some who believe that the Serrakin are oppressing the human population subtly and trying to control them, though what merit, if any, these claims have is not shown. The entire economy largely seems to depend on the Tech Con Group, a conglomerate which produces nearly every product imaginable. Not all Serrakin appear to remain on Hebridan, as some Serrakin are shown to be bounty hunters. (SG1: "Space Race", "Bounty")
The origins of the Serrakin people themselves are unknown. Thousands of years ago they came to Hebridan and liberated the people there from the Goa'uld, suggesting that, at least on a small scale, they were capable of challenging the Goa'uld. Curiously, they did not know the purpose of the Stargate despite this victory over the Goa'uld.
After this period, the Serrakin integrated with this branch of humanity and lived in harmony. As part of this union, the Hebridians were given the advanced technology of the Serrakin race.
Earth came into contact with the Serrakin on the planet P2X-005 when SG-1 encountered a crashed Serrakin vessel. However, the Hebridian prisoners of the ship tricked Stargate Command into believing that the Serrakin were a hostile race of native savages that killed their crew. The surviving members of the crew included Warrick Finn, who managed to tell SG-1 the truth and together they managed to apprehend them. This began a limited level of contact between Earth and the Serrakin race. It was here that Warrick, and later the rest of his people, learned of the Stargate. (SG1: "Forsaken")
Diplomatic contact between Earth and the Serrakin continued but had been slow to advance. Warrick unofficially allowed a level of technological exchange to occur between the two by asking Samantha Carter to help him win the race at the Loop of Kon Garat. This allowed SG-1 to visit Hebridan on a diplomatic basis. (SG1: "Space Race")
Some Serrakin were active after the fall of Herbidan, as a duo of Serrakin were among the Lucian Alliance bounty hunters that wanted Netan's reward for capturing SG-1. They were killed when Odai Ventrell attacked their Tel'tak, in order to eliminate the competition. (SG1: "Bounty")