Final answer:
Some of the flat characters in Harry Potter and the Chamber of Secrets include Colin Creevey, Mrs. Norris, and Moaning Myrtle who have little development and remain unchanged throughout the story.
Step-by-step explanation:
In the Harry Potter and the Chamber of Secrets, some of the flat characters include Colin Creevey, Mrs. Norris, and Moaning Myrtle. These characters have very little development, and their personalities and roles remain unchanged throughout the story. For example, Colin Creevey is always an enthusiastic fan of Harry Potter, Mrs. Norris is Filch's pet cat who is constantly trying to catch students breaking the rules, and Moaning Myrtle is a ghost who endlessly moans in the girls' bathroom.
Learn more about flat characters in Harry Potter and the Chamber of Secrets