In the desert area, get the dune hopper vehicle and head to the nothern most part. You will see a building like structure. Get a boost and the second you hit the wall hit the boost button and jump with the vehicle. You will go very high up and then hit the ledge(this may take a couple tries.) get out of your car and then turn to light jak. fly a little higher to a ledge and you will see and cracked wall. stand a little back and shoot the supernova(highest upgrade for peacemake) the wall will crush and you will be able to walk in. the first thing you see is a naughty dog symbol carved in the wall. To your right is a list of all the names of the creators and developers along with a huge precursor orb. since the precursor orb is shaped like an egg i asume the creators want you to know this is an egg. the big precursor orb is worth 300 normal precursor orbs. this is basically worthless if you have unlocked everything but its still pretty cool to find. this is a real egg because it is verified my the developers of naughty dog. Good luck!