Semasalli was a Dressellian crew member of the freighter Woebegone.
In 67 BBY, Semasalli was present when Darth Plagueis boarded the ship on its journey from Bal'demnic. When Captain Ellin Lah was killed by Plagueis, Semasalli joined his fellow crewmembers in attacking the Muun Sith Lord. During the fighting, Semasalli was dismembered, losing his left arm at the shoulder. He was rendered unconscious after the battle, and was aboard when Plagueis ordered the ship to be destroyed.
Semasalli is a supporting character introduced in the 2012 novel Darth Plagueis by James Luceno. In the novel, Semasalli has but a scant few lines and is killed early on, though this occurs outside the narrative.