Johnny Test/WMG

Johnny's sisters make him wear that shirt.

They make him wear it because they have no clue what the experiments are going to do in the long term. Because of this, they make him wear a shirt with a radioactive symbol to let people know it's a possibility.

Gil knows that Susan and Mary are attracted to him.

He's not interested because, well... they're trying too hard. Not in the No Guy Wants to Be Chased form, either, but in the "Mad Science will surely FORCE him to fall for me us!" form. He hasn't rejected them flat-out because pissing off the Mad Scientists is probably not the best plan - if they're willing to go to insane lengths now just to get him to fall for them, how would they react upon realizing they had NO chance with him? They don't seem likely to obey something like a restraining order, either... And then there's the fact that they already experiment on his pal Johnny... So he plays the fool and acts oblivious to their feelings, hoping that they'll eventually get over their obsession with him.

Johnny Test is Duke Nukem

He has the "radioactive" shirt, they have the same hairdo, and they have the same immature personality. Have Johnny grow into an adult, and you get Duke Nukem.

Johnny Test and Dexter's Lab take place in the same universe

Two things support this idea.

The Labrador and Owner from Dexter's Lab: A Story look very much like Dukey and Gil. Dukey must've wound up as Johnny's dog sometime later. Dukey must've also picked up a bigger vocabulary in the meantime.
Johnny's family seems like a gender-swapped counterpart of Dexter's. Johnny matches up to DeeDee. The Twins match up to Dexter except there's two of them. Johnny's Dad and Dexter's Mom are both obsessed with cleaning. We don't know enough about Dexter's Dad except he works outside the home, like Johnny's Mom.
- Don't forget that the enemies of both shows are geniuses in robotics and are in love with the hero's sister. However, Dexter's Dad isn't that much like Johnny's Mom; he's oblivious, goofy, still in love with his wife, and treats muffins as Serious Business. Johnny's Mom hasn't appeared a lot to really say anything.
- I always thought the similarities, especially with the gender-swapped roles and hair colors were Shout Outs.

Johnny and Dexter are related

Either Dexter's Mom or Dad has a twin brother or sister which is also either Johnny's Mom or Dad.

Whichever has Dexter's Mom as a sister, Mary and Susan must have got their hair color from their aunt's side of the family.

Johnny and Dexter were Switched At Birth

Johhny is De Dee's brother, Dexter is Susan and Mary's. Why didn't they correct this? It's a Government Experiment. Do idiot sibling affect Mad Scientists, and does order matter? They find that When the genius is younger, their sibling destroys their creations, while if they are older, they facilitate things, becoming a human guinea pig.

- Jimmy Neutron was the control group. A child Genius with no siblings to see how they behave with no siblings interfering.

Gil doesn't like Susan and Mary that way...

Because it is a case of Incompatible Orientation. Any straight guy would notice two pretty twin girls fawning over him. He seems a lot more interested in Johnny than in his two sisters. When ever the twins say hi to him, he'd completely ignore them and tell Johnny hi even though he didn't greet. Even when he's not around, he would tell the twins to say Hi to Johnny for him.

I'm not into yaoi, but if there was no sex, I'd read that fic.
In "Nightmare on Johnny's Street", Gil wants to take Johnny to a candle-lit dinner for saving his life.

The Art Evolution is the result of an experiment gone horribly awry .

Now everyone moves jerkily while consisting of vector curves and gradient shading.

The whip-crack sounds after Season 2 could probably be explained by this.

When Johnny was born, the girls did their very first experiment on him

It did two things,
1. Kept him moderately dumb, so he'd agree to their later tests.
2. Made him cartoonishly indestructible, in case of later failures.

Dukey has a new voice because Susan and Mary did some experiment on him because they got sick of his laugh.

Now Dukey's woobiness has gone Up to Eleven.

Johnny's father was just like Johnny when he was a kid.

Self explanatory.

Susan and Mary will split apart in adulthood

Susan will work for Global Dynamics because she is grounded in science. Mary will be recruited to the warehouse because of she is more likely to accept artifacts as fact.

Susan and Mary will fall out of love of Gil.

They're tired of him never noticing or remembered them, for their schemes to get his attention failed or backfired, and for always hanging out with Johnny. And also for always falling for Dukey's Gil impersonations.

Gil has a secret shrine to Johnny.

He does seem to like Johnny a lot.

Susan will eventually fall for Bling Bling Boy.

It's more or less of a "Gil won't love me so I'll just settle" type of thing.

Everything is a part of Johnny's dream.

It makes the most sense, right?

Susan and Mary are still his smart older sisters, but they're not smart enough to be teen scientists.
- Alternatively, Susan and Mary are only one entity: Johnny only has one older sister (either Susan or Mary, take your pick), but she has Split-Personality Disorder.
- ...Or, one of his sisters is dead, but he can't get used to the fact that she's gone.
Dukey is just a regular mutt, not a super-talking dog with mad Kung-Fu skills and a coffee addiction. Dukey's personality was most likely based on one of Johnny's uncles, a family friend, or a character that he saw on a TV show. Or all three.
Bling-Bling is just a really dorky kid with a crush on Johnny's sister whom also goes to his school.
The Vegans are his new neighbors that moved from a different country.
Gil, Bumper, Mr. Teacherman, and every other normal character exists, but they are exaggerated to a degree. For example:
- Gil isn't as stupid as he is portrayed. In fact, he and Johnny aren't even really neighbors. He is really an actor that Johnny saw in a movie, and Susan and Mary are his biggest fans. Johnny just thought that it would be cool to live next door to him.
- Mr. Teacherman is a strict teacher, but Johnny sees him as just mean and cruel for no reason.

The art shift can be explained as well. Season 1 wasn't a dream, but rather an idea for a story. Sometime between Seasons 1 and 2, Johnny got into an accident and went into a coma. Everything from the beginning of Season 2 until now is a part of his coma dream. Things seem to be getting less original and becoming more obnoxious and repetitive because he's starting to lose control of the dream and forgetting his life before the accident; this can also explain the voice changes in certain characters, like Dukey.

Basically, Johnny is living in his own ideal world.

Someone in the Johnny Test staff has a transsexual fetish.

Let's see:

One early episode had Johnny turn into a woman for a few seconds.
Another had Johnny crossdress during take-your-daughter-to-work day.
One had a device intended to make Johnny fall asleep. This device had several side-effects, such as turning Susan and Mary into boys.
Another episode has a cartoon where the Johnny and Dukey lookalikes have two scientist brothers.
Johnny frequently crossdresses when in a Girl Scouts-esque group.
In one scene of a villain team-up episode, an incarcerated Brain Freezer wonders if he would be nicer if he was born a girl.
Yet another episode has Johnny and Dukey travel to a world where everyone is genderbent.
One recent (as of 1/11/12) episode has Johnny and Dukey become female roller-skaters for a Roller Derby sport. Dukey gets amnesia and thinks he is really a woman.
Enough said.

Susan and Mary are the REAL main characters

We're just seeing it from Johnny's point of view.

This is really a Stealth Parody of bad and unfunny cartoons

Does it LOOK genuine to you?

At least one of the writers is a Johnny x Dukey shipper.

Watch a few episodes of seasons 4 and 5 and you might just come across an episode with some Ho Yay.

Examples:
- In "Dukey Jekyll and Johnny Hyde", specifically, the scene where Johnny is trying to get monster!Dukey to remember that he's not a monster, there's a flashback which involves Johnny and Dukey sitting on the beach, embracing each other, and watching the sunset together.
- In "Roller Johnny", the diagram with Susan and Mary's plan to change Dukey back into a boy involves almost the exact same scene with the sunset.
- In "Return of the Super Smarty Pants" just listen to Dukey's speech to get Johnny to fight the pants' control of his brain. You can't deny it's borderline Ho Yay.

Johnny Test (the show) is an Eldritch Abomination

How else could something so utterly wretched never be cancelled? It obviously is gaining power because nobody pays attention to it!
- Sadly, some people do watch this show. It's notorious for its rather creepy fanbase.
  - OH GOD IT HAS FOLLOWERS

This show's writers are little kids

I really, really hope grown men/women had nothing to do with this.

Scott Fellows cares little for the show.

Scott Fellows, (the creator of Johnny Test), has clearly written better shows. It wouldn't seem too out of reach, that Fellows cares little about the series by now, and doesn't put much effort into the scripts he writes for the show.
- I don't think he even has any input on the show anymore.

One of Johnny's ancestors is a dog.

This mainly stems from the episode involving Johnny's different personalities. One of them happens to turn Johnny into a dog(again). Since it's explained that his different personalities are based on his family's heritage, it more or less subtlety implies that Johnny has a dog for an ancestor. It could also explain Johnny's fondness for dogs and his hatred for cats.