This is map knowledge for DLCs 1 and 2, Onslaught and Devastation.
Cryptid Egg Hunt: this is a cross-mode Easter egg for both multiplayer (or safeguard) and Extinction modes. In each map of DLC 1+2 is a hidden bit of Cryptid egg sack. If you find and shoot all 4 in each DLC, you will receive 2000xp, then you go to a public game of Extinction, beat a hive to receive 10,000xp towards Extinction. That's 2000/10,000 for each DLC.
Easy way: Go to Squads> safeguard> play now. Then back out and start over until you get the DLC1 maps. Start safeguard, shoot the Cryptid egg during the Loot Round, leave, hunt for next DLC1 map.
For DLC2 (and each current DLC in the future): Go to Squads> Devastation (or current DLC)> safeguard> play now. This will only be the 4 DLC2 (current DLC) maps, real easy to get this done. Same as above, shoot the eggs during Loot Round, leave. Then repeat for each map.
Each one that you shoot will cause a pop up on the upper left of your screen, telling you that you got it.
Map directions: pause game, see map. Left = west, up = north, right = east, down = south.
Containment: middle north. Get on moveable dumpster. Look north east out of map for bump on rooftop. Shoot it.
Bayview: a bump on the bottom of a pier outside the map in the east. Can be seen from the ground by the east side of the lighthouse. Shoot it (best with sniper scope).
Fog: near the Satanic altar, in the wall of the pit in the caves. Shoot it.
Ignition: in one of the north east tunnels in the map. Quite large and obvious. Shoot it.
Unearthed: find the large 'Seeker' meteor middle south (that large rock sticking up). Go near it, peer below it from it's edge to view the egg. Shoot it.
Ruins: south east in a small structure just out of the playable area. Best seen from the lower eastern structure sticking out of the map. Shoot it.
Collision: go to the north east where the ship has collided with the bridge. Find the taxi; from the driver door (left side, not British), walk to the edge of the map by a square chunk of road leaning against the outer rail. Peer through there to view it at the bottom of the bridge support, at the water line. Shoot it.
Behemoth: start at the west end, walk east, along the northern edge until you get to the part that sticks out further north (by large yellow support). Stand there, look west and down to view the egg.
Good luck and happy hunting!
[more cheats for Call of Duty: Ghosts here]