Which character did the "Outstanding Voice-Over Performance" winner voice?
the "Outstanding Voice-Over Performance" refers to award = 'Outstanding Voice-Over Performance'; winner refers to result = 'Winner';
SELECT DISTINCT T2.character FROM Award AS T1 INNER JOIN Character_Award AS T2 ON T1.award_id = T2.award_id WHERE T1.award = 'Outstanding Voice-Over Performance' AND T1.result = 'Winner';