Final answer:
Dean Thomas suggests they might get a vampire for the Defense Against the Dark Arts teacher in their next year at Hogwarts.
Step-by-step explanation:
In Harry Potter and the Prisoner of Azkaban (HP3), Dean Thomas jokingly suggests that they might get a vampire for a Defense Against the Dark Arts teacher the following year. This suggestion reflects the students' apprehension and dark humor about the seemingly cursed position, as each year brings a new and often problematic teacher.
Dean Thomas's comment is made in a light-hearted moment and showcases the mix of dread and curiosity the students have towards the Defense Against the Dark Arts post.