|"When Worlds Collide"|
| Season 1, Episode 1|
|Airdate:||January 21, 2013|
|Director:|| Katie H. D.|
Erik H. D.
|Story:||Erik H. D.|
| Written &|
"Animated Short (Pilot)"
"Slumber Party Panic II"
Finn and Jake are notified that there is another human named Pen, and he is from Saturn. So he comes to Earth to visit Finn. Princess Bubblegum must try to make sure Pen is safe from danger in the Land of Ooo.
Finn and Jake are dancing in the Candy Forest when Princess Bubblegum (in her lab coat and wearing her glasses) comes running up to Finn. She starts yelling,"I found another human! But he lives on Saturn in the Land of Aaa, with my friend Princess Gumball!" At first Finn looks at Jake in confusion and then they both look at the Princess in confusion. Then she screams,"Follow me!, i'll show you!"
At Princess's laboratory she pulls them to her microscope to Saturn. They see Princess Gumball, Pen, and Nate looking to a solar system map and Earth is circled in red. Princess Gumball pulls them to a microscope to see Princess Bubblegum, Finn, Jake so they see each other. So Princess Bubblegum begins to work to a transporting devise so Finn and Pen could meet each other. Princess Bubblegum said that Finn and Pen might be twin-brothers, because they look just like each other.
Two days later Princess Bubblegum call Finn and Jake, and say the devise is ready. When they get to Princess Bubblegum's laboratory she starts the devise and a portal opens up to Princess Gumball's laboratory on Saturn. Two minutes later Pen, Nate(the Cat), and Princess Gumball are on Earth. "Hi,"Pen said. "Awesome!, There is another human then me, and were brothers!". Then Princess Gumball said to Finn,"Finn, Pen remembers a little about your parents". Then Finn almost faints, but he can only say,"Do...Do...you remember our mom?" Then Pen sighs and says nods his head and says, "Yes."
- It is reveled that Lady Rainicorn can speak more English than Korean. But she still usually still speaks Korean
- The next episode Slumber Party Panic II was originally going to be the first episode.
- The episode was originally going to be called "The Other Finn" then "I Have a Brother?"