In 3 1/2- to 4-quart slow cooker, place turkey thighs. In small bowl, mix tomatoes, tomato paste and garlic. Pour over turkey.
Cover; cook on Low heat setting 6 to 8 hours.
About 25 minutes before serving, cook couscous in water as directed on package. Increase heat setting on slow cooker to High. Stir zucchini into tomato mixture. Cover; cook about 20 minutes longer or until zucchini is tender.
To serve, remove bones from turkey. Stir gently to break up turkey. Serve over couscous.