So it's no surprise that fans have spent time and energy trying to prove that every film connects to those around it, sometimes looking a bit too close at a random Easter egg.

With the surprise success of Disney's Frozen, fans have come up with a theory that is out of this world, claiming another Disney hero is a long lost sibling of the starring sisters.

With Disney keeping quiet on any official canon, the theories are all in the name of fun, and using a bit more imagination in between releases.

We've done our best to lay out the theories that work – and the ones that don't – in our first Docu Series, exploring The Secret Family Relations Between Disney Movie Princesses.

Frozen IN-Tangled.

By now, every Disney fan knows where this theory starts: with a single split-second cameo from two other Disney stars.

But before we get into Queen Elsa's coronation, we'll have to explain why the throne is empty in the first place.

It's nothing new for a Disney hero to be without their parents, so seeing the King and Queen of Arendelle remove from the picture was less than shocking.

That doesn't make it any less tragic, with Anna and Elsa bidding farewell as their parents head out to sea for a two-week roundtrip journey.

The ship is lost at sea, leaving the girls without their parents – and Arendelle without a monarch.

After three years, Elsa is old enough to claim the crown, and the entire kingdom and visitors from far-off lands show up to celebrate.

The doors are opened, and Anna heads out to greet the guests, two of which are instantly recognizable.

Rapunzel and Flynn Rider, the stars of Tangled are impossible to miss, thanks to their hairstyles and clothing.

It might seem like a tiny easter egg, but it got fans thinking:

Frozen would have to be set after the events of Tangled for the cameo to make sense, so perhaps the two movies are more connected than they seem.

Fans have spun some wild theories, claiming Rapunzel and Elsa's mothers look alike because they're sisters, married to the kings of two different kingdoms.

One daughter is born with the gift of healing, thanks to a magical flower, while the other is born with control of icy magic.

It's impossible to actually prove the princess is there to see her cousin's coronation.

But Arendelle should have sent someone to celebrate Rapunzel's return home, and wedding. Like, say, the King and Queen?

Unfortunately, Frozen never explains where the Royal Couple is headed, or why, only that their ship sinks on the way.

But using the countries that the fictional kingdoms of Frozen and Tangled were based on takes this theory even farther.

Disney's animators took a trip to Norway to help create the mountainy kingdom of Arendelle,

and Rapunzel's home of Corona is likely inspired by 18th century Germany, the same place the Brothers Grimm wrote their famous version of the story.

That would put the two films on opposite sides of the North Sea, with the ship being sunk somewhere off the coast of Denmark.

Why does that matter?

Well, no Disney movie is explicitly set in a Danish kingdom, but one of the studio's most beloved classics was written by a Danish citizen, a fact that takes this theory into time-bending, shared universe territory.

The Little Mermaid.

The writer in question is Hans Christian Andersen, whose version of The Little Mermaid was a bit darker than Disney's version.

But some have claimed that the movie actually ties into Frozen directly, with the shipwreck explored by Ariel in the opening scenes the exact ship that Elsa's parents died on.

The theory can lose some steam with that twist, since it's a bit of a reach.

But the biggest problem is the climate: Andersen also wrote "The Snow Queen," which Frozen was based on.

And that's a better fit for the North Sea than a story filled with tropical fish and sandy beaches.

But don't worry, conspiracy fans, the shipwreck in The Little Mermaid can still come from Arendelle – it's just nowhere near Denmark, or the North Sea.

When the directors of Frozen were asked point blank about Elsa's parents' destination on Reddit, they gave direct answers.

Jennifer Lee said it was a wedding, with Chris Buck clarifying that the King and Queen didn't die on the ship at all.

In fact, it didn't even sink.

The ship, and the couple, survived weeks, possibly even months lost at sea until they washed up on a jungle shore, and had to build a home next to a family of gorillas.

Tarzan.

That's right, according to Buck, the King and Queen of Arendelle were the shipwrecked parents of the boy who would grow up to be Tarzan.

They get shipwrecked, and somehow they really washed way far away from the Scandinavian waters, and they end up in the jungle.

They end up building a tree house and a leopard kills them, so their baby boy is raised by gorillas.

So the storm didn't sink the ship, it just tossed it out into the Atlantic, to travel south to Africa before bursting into flames and sinking – something that happens pretty often in Disney's universe.

That might be a hard trip to believe, but in a world of ape men and magical attacks, a storm being really powerful is actually easy to believe.

Just to be clear, weird family relations in the Tarzan story aren't anything new, either.

In the original version of the story, Tarzan's real name would have been John Clayton – a cousin of the movie's villain.

Frankly, we're all for a different explanation.

There are still a few problems with the theory, but it's what director Chris Buck believes happened – and since he also directed Tarzan, he's kind of an authority on the subject.

It's still an unhappy ending for the King and Queen, but Elsa and Anna's brother finds a family and happiness of his own.

Even if the details don't match up, it's what the director believes is the true story.

As for the wrecked ship?

For those who love the idea of Ariel investigating it, who's to say it couldn't drift a bit farther before sinking?

After all, there's another hint that these locations aren't as far apart as you might think.

The Cinderella Factor.

To prove that these Disney kings, queen, princes and princesses really do share the same social circles,

fans can watch when Prince Eric is almost duped into marrying the wrong woman in The Little Mermaid.

A split second shot shows the King and Duke from Cinderella, having traveled to see the Royal Wedding.

And when the doors to Arendelle's castle are opened,

the first few frames feature a woman sharing more than a passing resemblance to Sleeping Beauty's Princess Aurora as well as The Princess and The Frog's Princess Tiana.

With all those details, it's hard to believe Elsa's parents weren't headed to the wedding of another Disney princess.

It isn't likely that Disney will ever confirm or deny any official connections, and in the end, they don't really need to.

Since the characters aren't likely to ever meet, it's enough to know that in the mind that helped to create Tarzan and Frozen,

Anna and Elsa's long lost brother in a far away land was the King of the Jungle.

The ship that got him there… well, that's just for fans to do what Disney is all about: use their imagination.

To summarize everything, the theory claims that Elsa and Anna are actually the sisters of Tarzan, since their parents lived long enough to deliver him as a baby to the gorillas who raised him.

A part of their ship kept on drifting until it came to rest on the ocean floor, where Ariel eventually explored it for trinkets.

The rest would be used to build a treehouse.

She would marry Prince Eric not long after, a prince who was apparently close enough to Cinderella's family to have her father-in-law, the King, and his right hand man the Grand Duke at the wedding.

Disney royalty apparently make a point of attending other royal weddings,

and Frozen's director confirms the King and Queen of Arendelle were headed to one when they disappeared.

It could have been Cinderella's wedding to Prince Charming, Aurora's wedding to Prince Phillip, or even Tiana's wedding to Prince Naveen, since they're both shown arriving for Elsa's coronation.

But if the Queen of Arendelle really was the sister of Rapunzel's mother, or they're just neighboring queens,

it's a safe bet they were headed to Rapunzel's wedding when they disappeared.

Not one to forget such a sacrifice, Rapunzel and Flynn made sure to see Elsa's coronation in person.

It's not as complicated as it may sound, if fans realize that the characters may be familiar, or even friendly, with stars of other classic movies.

Which all lead to one big question: are all Disney films part of the same shared universe?

They may never give a clear answer, so until then, let us know what you think! And make sure to subscrive to our channel for amazing movie fact videos and insightful documentries.