It's a tradition for family comedies to pimp kids for yuks, but we're feeling pretty yucky after watching a promo for NBC's new ''Tracy Morgan Show,'' in which a precocious prepubescent (Bobb'e J. Thompson) ditches a Muppet T-shirt only to strut out, shirtless, in a suit. ''This is what my look says,'' he boasts. ''I'm civilized, but I'm dangerous.'' Actually, the word that comes to mind is creepy.

