Sennari was a poison that had toxic effects specifically on members of the Trandoshan species. In the year 7956 C.R.C., Nack Movers, a Trandoshan hitman who allegedly received training from the Malkite poisoners, met his death at the hands of Ione Marcy, his girlfriend, and Cassilyda Cryar, his bodyguard. They administered the sennari to him through a beverage at his residence on the planet of Coruscant.
The Trandoshan's unique physiology interacted adversely with the toxin, causing violent convulsions that resulted in him knocking over various pieces of furniture, before he collapsed and died. During the investigation into the murder, Russo-ISC, a crime scene analysis droid belonging to the Coruscant Security Force, detected 11.3 units of sennari extract in Movers's blood. Inspector Tanivos Divo subsequently recorded this finding in the case file.
Sennari made its debut in the new Star Wars canon in the 2018 reference book titled Star Wars: Scum and Villainy: Case Files on the Galaxy's Most Notorious, authored by Pablo Hidalgo. The toxin initially appeared within the Star Wars Legends continuity, specifically in Tatooine Manhunt, a 1988 adventure book by West End Games for Star Wars: The Roleplaying Game.