Boxes and Boxes - S4.E4

There is a new branch of the store opening up across town and the stockroom manager, Mrs. Pennypacker (Cheryl Wagner) has a list of six mannequins to go there and Jeff is one of them. So They try and show and explain Mrs. P about Jeff's magic hat but she just thinks that Jeff is pretending. Later on, when Mrs. P tries out the hat herself, she eventually is convinced and sends another mannequin in his place.