As suggested in T124: Please find an alternative for the the default avatar icon that doesn't look like an encoding error, the outline of a fictional country or a random splat. I found it really distracting at first. Now that I know it's some kind of "duck" I can't unsee it. Still I think we can do better.
Here is a very simple suggestion. Yes, the resemblance is intentional. ;-)
(examples removed, they were showing wrong images from imported Bugzilla)