Trophy description - Complete the Egg-Stra XP challenge and then activate a generator in the Nemesis DLC package.

Trophy - Bronze

Like in the previous three DLC's you must find the four eggs in the multiplayer maps and shoot them. Then enter the new extinction map and activate a generator and the achievement will unlock. There is one egg on each of the nemesis maps.

Dynasty - In the south west of the map, there is a boat with red sails in the distance, with the egg on it.

Subzero - In the north east of the map the egg is located inside a missile silo.

Goldrush - In the south of the map inside the cave you can stand near the edge and aim down the small cave on the left.

Showtime - In the west of the map next to the podium you have to climb the black boxes and jump to the platform on the right and it is behind the glass.

Then play extinction on Exodus and activate a generator to unlock the achievement/trophy.

The video shows the exact locations of each egg.