The Tlönians were a species of sentient arachnoids from the planet of Tlön in the Tlönia system. They were known for their poison-sacs and habit of preying on starships imprudent enough to cross their frontier. By the 6100s BBY, they had been exterminated by the Mandalorian Crusaders. Prior to their extinction, the Tlönians crafted a particular type of shield. By the time of the Clone Wars, one of those Tlönian shields ended up in the possession of a genetic decoy of the terrorist Zeta Magnus.