Grand Admiral Thrawn returned in Ahsoka Season 1, Episode 6, "Part Six: Far, Far Away." Nightsister Morgan Elsbeth and former Jedi Baylan Skoll located the Imperial leader on the distant planet Peridea. Thrawn (played by Lars Mikkelsen), had disappeared nearly a decade earlier. The space faring Purgill whales had transported Thrawn and Rebel Ezra Bridger to parts unknown. The climatic moment happened in 2018's series finale of Star Wars Rebels. Elsbeth discovered his likely whereabouts in Ahsoka's second episode, "Part Two: Toil and Trouble."
Source：https://www.cbr.com/ahsoka-perieda-witches-orchestrate-thrawn-arrival/
