S1·E18 Arthur's Cousin Catastrophe

The Read Family is having a big reunion, with aardvark relatives from all over coming. Arthur normally enjoys the festivities, such as sack-racing and swapping stories, but finds himself hiding because he's worried that his cousin Mo has a big practical joke planned for him. He remembers her being awful to him in the past and is sure that she has something big planned. However, his worries might just be unfounded.