GTA 5 is absolutely crammed with Easter Eggs, including Aliens in GTA 5, unexpected Cameos, and other intentionally well-hidden, cool stuff. Due to the sheer volume of Easter Eggs and references in GTA 5, this section is divided into multiple subsections.
Below you’ll find Easter Eggs in the classic sense: Hidden, goofy things the developers added just to be discovered GTA 5.
Since the initial launch of Grand Theft Auto 5 in 2015, players have sought the truth behind the secrets that lie beneath the rocky face of Mount Chilliad.
While UFOs definitely do exist, and the FIB certainly doesn’t want you to know about the existence of extraterrestrials, it turns out that Mt. Chilliad itself is not necessarily the secret to interstellar travel we once thought.
As shown in The Doomsday Heist update, Mt. Chilliad is in fact home to an abandoned military bunker and missile silo. Of course, it ends up being used to potentially wipe out all life as we know it, but at least we finally got those jetpacks we’ve been after.
The bunker is entered via a hidden cargo door leading into a tunnel network beneath the mountain, and contains a massive government facility as well as the missile silo and warhead storage.
A cryptic painting on the wall of the Cable Car station atop Mt. Chiliad was one of the earliest sources of intrigue for GTA conspiracy-hunters.The main map is remarkably similar to the shaft and chamber layout of a pyramid, suggesting the possible existence of a subterranean dungeon. Also scattered around the image are a number of smaller markers. While the meaning of many of the symbols within have been encrypted, the large icons of cracking egg, a spaceship, and a humanoid form remain an intriguing puzzlement.
The symbol matches the UFO depicted in the Cable Car station painting. On the back of the platform it reads “Come back when your story is complete.”
The carefully hidden painting beneath the platform atop Chiliad’s highest point is the sighting point for a well-documented postgame Flying Saucer appearance, which takes place late at night during thunderstorms.
EditOther Theories and Connections
Dedicated players have used exploits to spawn Vehicles under the map. Using their new-found mobility, they have discovered hidden FIB textures beneath the Mt. Chiliad platform and strange objects beneath Ft. Zancudo. 
Some players speculate that the Mt. Chiliad Map should be laid over the GTA 5 pack-in paper map to reveal a number of significant locations. Current efforts center around centering the map above the northward edge of the island, though this produces no discernible explanation for the three main Glyphs.
An alternate theory (image below) involves lining up the eye at the top of the mountain (red dot) with the glyphs on the the side of the mountain (green dots) leaving one half faded glyph (green circle).
Image Provided by GTA Forums
Glyphs line up as per the image below:
While intriguing, these theories fail to address the purpose of the connecting lines between Glyphs, as well as the three large symbols. Source code for the 1.12 update reportedly includes Jet Pack references.
Want to see the skeleton of a gigantic Sea Monster (aka Whale Skeleton) in Grand Theft Auto 5? We show you where you can find it.
The bones can be found off the west coast of San Andreas, south of Chumash.
Many other paranormal oddities are scattered around San Andreas.
The Ghost can be found at night between 23:00 – 00:00 on Mt. Gordo north of the lighthouse. She’ll disappear when you approach her. The name “Jock” is written in blood next to her. If you search the internet for the “Who Killed Lenora Johnson?” (Lenora’s murder being the reason for the Letter Scraps collectibles), a page has another murder mystery titled “Blood on the Rocks.”
The article tells that the ghost is Jolene Cranley-Evans and that her husband is suspected of pushing her off the cliff. Her husband, Jock Cranley, later moved to Los Santos to become a famous stunt man and is currently running for governor of San Andreas. He is referenced during one of Trevor‘s Strangers and Freaks missions. During this mission you must steal celebrity items for a man named Nigel. When Trevor encounters Nigel, Nigel mistakes him for Jock and does so until Nigel’s missions with Trevor ends.
The Ghost is located off the East Coast of San Andreas near the El Gordo Lighthouse.
Switching to your IR scope reveals him clearly.
There’s much, much more to this easter egg…read our complete guide to one of gaming’s deepest secrets!
You can have a conversation with him. He’s a nice zombie.
GTA 5 has so many incidental references, nods, and inside jokes that we gave them their own page! Head on over to References to Movies, TV, Games and Pop Culture and see what’s hidden in San Andreas.
Beyomd Aliens, Ghosts, and pop culture references, there are a number of other intriguing things to find in San Andreas.
In the Vinewood hills there is a mansion that some of you may find familiar, it’s almost a complete replica of the Playboy Mansion.
Night time parties at the Mansion get a little wild.
On the cliff face of Mount Chiliad is a texture of a face of someone, possibly one of the developers?
The Face appears on the mountain’s north slope not far from the cable car station. FInd it on our Interactive Map!
San Andreas is dotted with graffiti left behind by the Infinite 8 Serial Killer.
By following clues left in these scrawls, especially in the prison, players can locate the bodies of his victims hidden in the following location.