9. Powerpuff Girls, Samauri Jack, And Dexter's Lab
Powerpuff Girls, Samurai Jack and Dexter's Lab were three of the most iconic Cartoon Network shows of all time, but wait, do they all take place in a shared universe?
Apparently so. First of all, there's an episode of Samurai Jack where you can clearly see a billboard that's ripped straight out of Powerpuff Girls. That's lead a lot of fans to speculate that Samurai Jack takes place in some sort of post-apocalyptic Townsville way in the future.
But taking this a step further, there are several Powerpuff Girls episodes where Dexter makes a cameo appearance. In one scene in the episode Forced Kin, he shows up in a crowd looking up at Mojo Jojo's giant robot. In another episode, he can be seen sleeping in the girls' kindergarten class.
In fact, there's even an episode where you can see Bubbles holding a bunch of toys including one of Dexter, so he apparently is famous in this world. The Justice Friends also connect the two, a group of superheroes from Dexter's Lab that also show up in Powerpuff Girls.
So then that means Powerpuff Girls, Samurai Jack and Dexter's Lab all share the same crazy animated universe. And while the Samurai Jack thing is still largely a theory, the connection between Dexter's Lab and Powerpuff Girls has actually been confirmed by the creators.