Arthur and his friends find a snake in the woods and sneak it into Arthur's room with a shoe box. However, the snake gets loose in Arthur's house and Arthur learns he is not allowed to keep snakes in the house. To make matters worse, the kids cannot remember if it is a venomous coral snake or the similarly-colored, but harmless kingsnake. They try to find and get rid of the snake without Arthur's family noticing. Muffy and Francine are best friends, but Muffy does not like soccer and Francine does not like shopping. After Francine and Jenna discover that both of them like soccer, Muffy searches for a new best friend who likes the same activities as her, but none of them are perfect matches.