It seems as if there is a new avatar that will be released soon, related to the recently released game AAA's Revenge:
The requirements are unknown, but thanks to mr_d666 we know it's obtained when submitting your score in AAA's Revenge. It seems that if you do have the opportunity to receive it, you'll get an error message saying the avatar does not exist as of posting.
We'll post an update once we know more.
I was starting to wonder why nobody posted about this e_e