Pokémon S08E11 - A Cacturne for the Worse

As the heroes sail to May's next Contest, May finds a boy named Harley. She speaks to him a bit and meets his Cacturne and eats his cookies. Harley is annoyed at the girl, who becomes his rival that he wants to crush. During the Contest, Harley gives May some false advice, which May accepts, only to find out Harley tricked her. Just as she faces Harley, he uses another trick up his sleeve to deceive May even more, wanting her to be defeated.