Mork & Mindy/WMG

WARNING: Spoilers ahead.

Exidor is (or was) the prat-falling guy from Catalina Caper.
And now you know what drove him mad.

The whole series is a daydream/hallucination of Sy Parrish from One Hour Photo.
Consider, if you will, Sy Parrish. A lonely, introverted, deeply troubled middle-aged man. No family, no friends, no lovers. So, he escapes to a world where he is young, dark-haired, spontaneous, and charismatic in a weird way. He has a social life and even lives with a beautiful young girl who loves and cares for him deeply, as he does for her. But because of his traumatic past, he can't think of himself as human. And he certainly can't think of himself in a physical relationship with this girl. They kiss, and nothing more. Even when they get married, the uh, details of the honeymoon are absent. The events of "season 4" are clearly signs of his mind becoming more and more unstable.
 * Note that if we couple this with the above theory, that would mean Catalina Caper is also his daydream. This seems improbable.
 * Alternatively, One Hour Photo is Mork's nightmare.

Mork is Jesus.
An otherworldly being with long hair and some wild ideas comes to Earth. The show says he's here to learn from us... but in a lot of ways, he is the one teaching us. He is innocent and pure of heart, and he has shown many times that he would sacrifice himself for Mindy. In fact, there was one episode where Mork has a "birthday" and must re-energize himself at the right time with an egg-shaped "gleek", or else he'll die. Well, he starts acting weirder than normal, and Hilarity Ensues as usual. But the ending has him desperately trying to find the gleek in a carton of eggs; he smashes egg after egg against his head, but when he finally finds the gleek, he collapses before he can use it. Somehow he gets revived anyway. Divine intervention, perhaps?
 * This does not mean that Orson is God. Everyone knows Robin Williams is God. Mr. Williams somehow willed an alien doppleganger into existence. He knows this, which is why he isn't fazed when Mork shows up in his dressing room.

Mindy Is Haruhi Suzumiya
She recreated the universe into a 1970s sitcom and got a time travelling alien esper boyfriend.
 * Wait, so does this contradict the above or what?
 * Maybe.
 * No everyone knows that Robin Williams is just another aspect of Haruhi and Haruhi is just another aspect of Robin Williams.

Mearth was conceived by Mork performing oral sex on Mindy.
More specifically (spoilered because it's kinda Squicky): Mork was the one who was "pregnant" (he laid the egg) with Mearth. He laid the egg out his belly button, so the egg must have been developing in his stomach (or the Orkan equivalent thereof) beforehand. And it's implied that Mearth was conceived sexually. This is the most logical conclusion.
 * As much as I really want to dispute this, I can't. Good call.

The final episodes are out of order.
"The Mork Report" takes place sometime before the events of the 3-part "Gotta Run", meaning the series really does end with Mork & Mindy falling through time together. What happens next is a whole other WMG.

Alternate theory #1: The final episodes are in order, and Mork & Mindy got rescued.
Perhaps by The Doctor. First the rescuer took care of Kalik much like he did to the Family Of Blood, and then he took Mork & Mindy back to Boulder, where they fixed the apartment and lived happily ever after.

Alternate theory #2: The final episode takes place in Instrumentality.
A happy ending that makes no sense whatsoever in the continuity? Gotta be Instrumentality.
 * And not just anyone's Instrumentality, either. The opening credits say "Directed by Robin Williams". Perhaps we should discuss the greater implications of that.

Mork from Ork is MORK OF DA ORKS!
Rapid-Fire Comedy is just like More Dakka but with jokes! Sooner or later Mork gets fed up with all the idiocy he sees with us puny humies, Orson becomes Gork, and in 40000 years or so he launches his WAAAAAAAAAGH!

Orkans are hermaphrodites
Even though Mork is otherwise male, he mentions in the pilot that it's hard to tell if men date women on Ork because "parts are interchangeable". In later episodes it's implied he does have something similar to human male genitalia (for example in "Mork's Vacation" when he switches bodies with another alien, he tells Mindy not to let them run away with the good parts "Especially that"). If we take all of this to be true (and ignore the fact that the show can't keep it's continuity straight), then, well, this is the logical conclusion. None of this seems to play a part in Orkan reproduction (see the Mearth's conception WMG above). Still, that must have one wild honeymoon.
 * Alternate theory: female Orkans are similar to hyenas, if you get my drift.

The Animated Adaptation takes place in an Alternate Universe.
It's the only way to explain away all the contradictions from the original series.
 * One good thing about said universe Mork is more powerful, with abilities not seen in the original series.
 * But on the other hand, everyone has the intelligence of cheese. And then there's that stupid pink dog-thing sidekick.
 * It's definitely an alternate universe. One episode has Mork's parents showing up, when in fact, Mork was a test tube baby in the original series (they kept the aging backwards thing though). Clearly the series is a High School AU written by a bunch of people who just didn't care (and were probably on several illicit substances).

Mork knew all along that his penpal wasn't the real Peter Pan.
And at the end of the episode, he actually was the one levitating him. He simply lied to Mindy to make her believe.
 * Well duh, everyone knows Mork is the real Peter Pan.