I'm not sure how to interpret the Malfoy ferret story, except possibly as an attempt to gain Harry's confidence by choosing his side. Or as something which seemed like it was what Moody would do. But then that class, it's impressive how it works both on the surface level when you think it really is Moody, but also when you know the truth. What he does towards Neville seems tactful and a sign that he's nice, when of course it's just some far-seeing planning to help Harry with the second task - six months in advance. It's really immensely creepy that this guy would go and be nice to Neville. I'm actually wondering now, does Neville ever find out who this fake Moody was? Because that must be horrible for him, if so... And how does Neville react later on to Moody, in either case?

Karkarov: a bad guy who actually is a bad guy! Well, sort of.

Hermione continues to be way more mature than the boys, although her naiveté in the way she tries to recruit people for SPEW shows she's still finding her way herself.

Fred, George and Lee: Proving themselves to be careless and somewhat immature in comparison to the trio (or at least Harry and Hermione), what with the raving about how "cool" Moody is.