40 years ago ... deep underground in a secret laboratory in the National Security Agency Special Projects Building 666, somewhere in Washington, DC ... a secret operation takes place.  The goal ... alter a once aquatic creature so it can now breathe air!  Change a being's genetic makeup to a new code ... a new pattern ... a new matrix that can be studied, learned, and finally .... replicated.   Replicate a new creature ... no!  A new SPECIES!!!  Create an army of super strength and endurance .... Creatures.  The army of the future.......... 
The operation proceeds well.  The Creature's gills are removed and replaced with ... baboon lungs.  A medical first ... achieved in the name of the Cold War Arms Race! 
The operation done ... the wounds sterilized and sealed ... the Creature is prepared for his new life amongst the air breathers and surface dwellers.
One final step remains ... to free the creature into the wild and observe him.  If all test complete successfully, recapture the Creature, obtain samples of his DNA, and begin to clone him using the Agencies top secret procedures.
The tests go well ... the Creature responds and reacts as the Military scientists have hoped ... lightning reflexes, phenomenal strength, and ever increasing endurance.  He truly is the weapon they had hoped for.  Imagine a platoon ...no ... an army of these Creatures attacking the enemies of the country!

Then, something goes horribly wrong.  The plans, the contingencies, the orders and preparations - all go awry.  The Creature evades recapture - evading and escaping the best trackers the Army and Marine Corp have.  He is gone.  Somewhere in the rolling hills and rambling streams of Northern Virginia ...

The Creature Walks Among Us!

Jump forward in time.  The year ... 1991.  The Cold War is coming to a crumbling end.  The feared Eastern Block is in chaos - the Soviet-controlled puppet states have seized their freedom from the teetering regime in Moscow.  Finally, even the Soviet political machinery can no longer keep their hold on their own country.  The Soviet Union literally ceases to exist.  In its crippled, crumbling wake are the waves of revolt and strife within what is now called ... Russia.  The Cold War is over.  The reason for many US agencies and top secret programs waver - are called into question - and vanish.  In their place are tomes of once top secret documents, films, and other media that suddenly become available for those who wish to search them out.
Once again accelerate thru time.  The date: today.  The place: the top secret Headquarters of ... the Gi Joe Adventure Team - buried deep in the privately held forests of Northern Virginia.  One of the last remaining bastions of men and women the world can still truly call ... heroes.
The clam, quiet solitude of the dense forest is suddenly disturbed with a throbbing noise.  The noise becomes louder and louder, until it is recognizable as that of a small, one man helicopter.  Into sight comes the Adventure Team Rescue Copter - carrying information for the Adventure Team Commander that is so sensitive, it must be hand delivered!
At last - the lone pilot's destination comes into the view - the Adventure Team Headquarters.

The AT Commander receives the news from the Copter Pilot - one of the GI Joe Adventure Team has uncovered incredible information!  Somewhere in the Virginia countryside is a being of incredible capability.  A being of super-human strength, endurance, and ... cunning.  It is called - simply - The Creature.

The Commander forms a plan and relays the information to his communications chief - "Inform all AT units in the area - we are going to find this creature, capture it, and change it back to what it should be - a being of the sea!  And we will then release it back to ITS world."

After dispatching his team to find the Creature, the Commander notices that buried in his information packet is the location of the US Government installation that first did the surgery on the Creature.

"We will need that facility once we find him" surmises the Commander "I had better dispatch a team of our best surgeons to that facility to prep it ..."

The Mobile Command Center receives the orders and relays them out to the units in the field ...
The various units of the Adventure Team form and begin the search, based on information the AT Commander sends them.  All of the various vehicles are pressed into service ... the Troubleshooter ...
... The Mobile Command Center excursion pod ...
... the Personal Escape Car ...
... and many other vehicles.  As the Team proceeds deep into the dense forest, they come across a startling discovery.  Could this mean the end of their quest?  Could they have searched in vain!  Is this the remains of the world's greatest secret?
No ... it is not!  It is the sad, lonely skeleton of a member of the original capture team.  No one will ever know what happened to him.  Did he get lost, lose his bearings in the dense forest - wander for days - and finally drop from exhaustion and dehydration?  Or did he perhaps fulfill his mission - and find his charge - only to be vanquished by it?  No one will ever know....   The Adventure Team pushes on until ....
... they come upon an obstacle in the way.  A tree .... where it seems there should be none!  The Adventure Team Smoke Jumper leaps out of the command jeep and immediately attacks the blockage.
Unseen by the smoke jumper is an approaching shadow.  Studying his moves ... watching him ... waiting.  And then ... motion out of the corner of his eye!  What is that movement?  A tree?  An animal?
 
Realizing the Smoke Jumper has but moments to live, the Land Adventurer uses his ATV to pin the Creature to the ground ...
With lynx-like agility and elephant-like strength, the Creature extracts himself from the six-wheeled prison and turns the tables on his captors.
Unbeknownst to the Creature, one of the Joes has been able to sneak up behind him with a capture net.
Caught!  The creature is entangled in the giant net!
After tranqualizing the Creature, the Adventure Team sets out for the Headquarters.
Later ... in the same government installation that gave birth to the mutated, air-breathing Creature, a team of GI Joe's finest surgeons work on restoring the Creature's natural underwater breathing ability.

And, as life always seems to have its twists and ironies, one of the Doctors working on the Gillman is the granddaughter of the nurse who originally assisted in the operation that first turned the Creature into an air-breather!

After surgery, the Joe surgeons place The Creature into the Stasis Recovery Tank.  They then prepare him for his long journey back home.  Back to the Amazon.  Back to HIS world.
After a long journey to the dark reaches of the Amazon jungle, the Creature is returned to his environment.
As the Creature shuffles off into the river, and finally disappears beneath its calm surface - Joe can only wonder ... "Is the Creature alone? Or are there more like him.  He has seen our world ... will he want to come back?  Alone?  Or with others?  As friend ... or as foe?"