Infected Codes -

$1 Avatar
Preview the $1 Avatar and press to spin him. After two full rotations, stop the spin so that you are looking at his back. Then, press , (x2), , .

 Bloodrayne
Successfully complete all missions.

Chimaira
In mission 29, kill a zombie near the Chimaira sign then get the avatar that it drops. The sign is located in the long street section under the park at the top of the map.

Santa Claus
Successfully complete all missions.