Animagus, but I liked the joke quite a bit.
This chapter was fun to read as well. My favorite parts were the Crucio-insentive, the conversation about animagi vs. occlumensi (I have NO idea what the plural for occlumens is), and the bit at the end with Curious George and Peeping Fred.
Author's response
Hey, I am still a bit uncertain about animage/animagus/animagi! It does make a good running joke. I am glad you had fun reading it. Harry has become a bit jaded and sarcastic. I think the tone of the story keeps that in the forefront of the reader's mind.
Jim