"Tricks" by Ellen Hopkins is actually a collection of short stories, not a single novel. This means there are many different characters featured throughout the book. It's not possible to list them all without knowing which specific story you're interested in.
To help me give you a better answer, please tell me:
* Which story from "Tricks" are you interested in?
* Are you looking for the main characters, or all the characters?
Once I have this information, I can provide you with a more specific list of characters.