Lakesis, a witch belonging to the Nightsisters of Dathomir and identified as female, was among the three Great Mothers who entered into an alliance with Grand Admiral Mitth'raw'nuruodo of the Imperial forces. She played a role in summoning Nightsister Morgan Elsbeth and her forces to the planet of Peridea. Lakesis, along with the other Great Mothers, foresaw the coming of Ahsoka Tano, a Jedi Knight whose presence would obstruct their objectives. After agreeing to employ their dark magick, Lakesis aided in locating Tano's vessel and created a delay for her and her companions, enabling the transfer of their cargo to the Chimaera. Subsequently, she and her fellow sisters initiated Morgan into their sisterhood and resurrected the Night Troopers who had been slain by Tano, Sabine Wren, and Ezra Bridger to impede their progress. Lakesis was present aboard the Eye of Sion during its transition into hyperspace for the journey back to the main galaxy.
The character of Lakesis made her debut in "Part Six: Far, Far Away," which is the sixth episode of the Ahsoka television series, with Jane Edwina Seymour taking on the role. Although her identity was not explicitly revealed within the episode itself, the character's name was confirmed in the episode's end credits. Drawing from Greek Mythology, Lachesis, bearing a similar name, was one of the three goddesses known as the Fates who were responsible for determining destiny. Lachesis specifically was responsible for determining the length of the thread of fate. This mirrors the claim made by Lakesis and the other Great Mothers, asserting their ability to perceive and comprehend the threads of fate and destiny.