A ravenous Karkarodon, Riff Tamson was a ruthless Separatist commander placed in charge of operations on the water world of Mon Cala. Count Dooku tasked him to disrupt the fragile peace between the Mon Calamari and the Quarren. Though present on the planet as a Separatist envoy, he secretly conspired with Quarren chieftain Nossor Ri to bring the Quarren into the war on the side of the Confederacy. Though Nossor believed he was doing what was best for his people, he had no idea of the true extent of Tamson's wicked plans.
Tamson specifically targets Prince Lee-Char, for he finds the young royal a threat. Though Prince Lee-Char is neither physically imposing or seasoned by conflict, the young Mon Calamari is nonetheless a symbol of hope that Tamson finds most dangerous.
Tamson is answerable to Count Dooku, who monitors the Karkarodon's progress from afar. Tamson reports frequently to Dooku via hologram, eager to be rewarded with gifts of power from the Separatist leader.
Anakin recognizes Tamson as a dire threat to peace on Mon Cala. Despite Anakin's abilities, even he cannot resist the overwhelming number of droid and Quarren enemies, and is captured and brutally interrogated by Tamson and his henchmen.
Senator Amidala desperately tries to negotiate peace between the Mon Calamari and the Quarren, trying to find common ground among the underwater people. For this, Tamson seeks to capture Amidala, and he also knows that by threatening the Senator, he can force the Jedi to comply to his whims.
A beautiful world of oceans, Mon Cala's serene surface hides undercurrents of hostility among its native Mon Calamari and Quarren people. It's the perfect playground for a ruthless troublemaker like Riff Tamson.