Exo Zombies is an upcoming Game Mode in Call of Duty: Advanced Warfare
The first so called 'Appearance' of Exo Zombies was on the map Riot playing the Game Mode Exo Survival at Round 11. This was a teaser and showcased a short period of gameplay. During the period of gameplay, the player had to (obviously) kill Zombies afterwards, the player was tasked with reaching a Extraction Point After reaching the point, a cut scene starts, in which the character Gideon is mauled by a zombie and left dead.
In the up and coming DLC Package due to be released on Jan 27, Havoc, Exo Zombies will be released. A new Mystery Box will be present along with various Exo Zombies. Some zombies eyes are coloured Yellow, Red, or Blue.