Bolla Thoath served as the second-in-command of the Star Destroyer Whirlwind under Captain Blitzer Harrsk. He died over the forest moon of Endor during the Battle of Endor, when the ship suffered an explosion that also heavily injured its captain. A piece of durasteel stabbed through Harrsk's left eye and his left frontal lobe, causing two personalities to develop. One was an irrational and megalomaniacal version of his former self; the other personality was Thoath. Throughout the rest of his life, Harrsk would suffer from multiple personality disorder, alternating between the Harrsk and Thoath personas.
Eight years after Endor, Harrsk barely survived Admiral Natasi Daala's poison gas attack at the meeting on the Tsoss Beacon. The Thoath persona decided to end Harrsk's irrational campaign and plunged his TIE shuttle into an asteroid. Harrsk finally realized Thoath had been dead all along, but was too late to stop the shuttle from crashing, killing him.