First releasing on the original PlayStation all the way back in 1997, Gran Turismo quickly became one of Sony's staple franchises, right alongside the likes of Spyro and Crash Bandicoot. And while those purple and orange mascots have parted ways with PlayStation's exclusive club, Gran Turismo still makes the occasional appearance every few years, often pushing the technical boundaries of whichever console it lands on.

Over the years, Gran Turismo has had a fair few entries, with eight mainline releases, and eight secondary titles, bringing the total to 16 games. Making all these games is no easy feat, but during the process, the developers managed to sneak in a few little in-jokes and references, some of which have gone down in history as some of series' best Easter eggs.

RELATED: Gran Turismo 7 Split-Screen Has a Serious Problem

Trial Mountain's Monkey and Loch Ness Monster

Gran Turismo Loch Ness

One of the most infamous Gran Turismo Easter eggs dates back to Gran Turismo's fourth entry and has cropped up in every game mainline entry since. On the game's Trial Mountain track, if the player heads to turn 13, they can see a creature resembling the iconic Loch Ness Monster, coming to meet two figures on a small rowboat. In Gran Turismo 7, the rowers are gone, but the Monster still appears in 5-minute intervals, stretching out of the water.

At turn 6 of the track, a small, pixelated monkey can be seen atop a tree branch that stretches above the track. Over the years, this monkey has received continual graphical updates, going from a pixelated blob in Gran Turismo 3, to a fully rendered HD model in the latest entries.

Jenkins The Cat

Gran Turismo Jenkins cat

Another animal-related Easter egg, "Jenkins" the cat can be found during Gran Turismo 5's Kyoto track by using the game's photo mode to go behind a fence, and zoom in on a small shrine. A detailed model of a cat will be sitting there, fully-animated.

This Easter egg actually has quite a sweet story behind it, as the cat belonged to a Polyphony employee who got married during Gran Turismo 5's development. As a wedding present, his co-workers decided to model his cat into the game. Although its real-life counterpart's name was "Primary," fans lovingly refer to this little feline as "Jenkins."

Trial Mountain's Hidden Faces

Gran Turismo Faces

Possibly the creepiest of Gran Turismo's Easter eggs, Trial Mountain is also home to some hidden faces. Found just before the Loch Ness Monster turn-off, these faces can be seen etched into the ground. With a similar appearance to a Rorschach test, this image evolves the more the player stares at it, with more faces becoming apparent.

Hideo Kojima

Gran Turismo Hideo Kojima

Though Gran Turismo Sport wasn't met with a great deal of critical acclaim, it did still pack in a few Easter eggs. One of the more memorable Easter eggs is that Metal Gear Solid creator Hideo Kojima can be found in the crowd during several of the game's tracks, sporting his usual glasses, hair and beard.

Back To The Future

Gran Turismo E Brown

Gran Turismo 7 isn't being received too well right now, with some pretty rough microtransactions ruining the experience for many players, but despite that, the game does have a few fun Easter eggs. One of these can be found during the game's American Sunday Cup, where the player will be given the wheel of a 2004 Delorean. If the player checks the scoreboard during the race, they'll notice that their driver's name is E. Brown, which is presumably a reference to Back to the Future's Dr. Emmet Brown.

Cow-Abducting UFO

Gran Turismo UFO

Another Easter egg from Gran Turismo 7, if players head to the Mount Panorama track and park up right next to the field full of people, they should be able to see a UFO fly in. It will then pick up a cow, and zip away. It takes a few minutes for the UFO to appear, but the absurdity of the situation is more than worth the wait.

MORE: Gran Turismo 7 is Being Review Bombed