In Prototype 2 for the Xbox 360, there are five avatar awards that you can unlock, but they are apparently tied to specific online events.
You have to have online access, and download the Radnet addon. Once you do, check the Events screen for more details once they become available.
So far I’m hearing that it will be some time in May before they are available. I’ll post more info as it comes out.
Here are the items that will be available:
Alex Mercer Outfit
James Heller Outfit
All but the shield will have a male and female version available.