Monkey Quest is no longer actively maintained. The game was shut down by Nickelodeon in 2014, and the servers are no longer operational. This means you can't access your account, change your avatar, or delete it.
If you want to remove your account information:
* Contact Nickelodeon: If you have any concerns about your account data, you can try contacting Nickelodeon directly. They might be able to assist you with any remaining information.
* Delete your browser data: This won't delete your account information, but it will remove any saved login data or cookies related to Monkey Quest from your computer.
While you can't directly delete your avatar, remember that the game is no longer active, and your data is likely inaccessible.