Teachers can change the name on their classes to anything they want! Class names can be up to 50 characters long. A teacher cannot have two classes with the same name.
To change the name of your class, click on the class you wish to rename from your home screen, then click on the Settings tab.
You will type in the name you wish to view for your class in the "Class Nickname" field and then remember to click on "Save" to complete the renaming.