MICROWAVE margarine and peanut butter in 2-qt. microwaveable bowl on HIGH 30 sec. to 1 min. or until margarine is melted, stirring every 30 sec. Stir until well blended.
STIR in dry pudding mix and half-and-half. Microwave 1 min.; stir. Microwave an additional 4 to 5 min. or until thickened, stirring every min. Cover surface of fondue with plastic wrap to prevent skin from forming. Cool slightly.
SERVE with assorted cut-up fruit or animal crackers for dipping.