Wow, I didn't see that coming. I didn't think Ice King's origin would take place before the Great Mushroom War. BTW, it's Bigfoot in the picture above, it's making fun of the old Bigfoot photo in the lower right corner.
Fan art is already appearing online of pre- Mushroom War ice king (Simon) and his beloved "princess" Betty. A nuclear war could create a nuclear winter that be fell Simon/Ice King. Another thought that popped in was I thought Ice King stole his crown. This new insight makes the Ice King and even more tragic character.
Some speculation online about Doctor Princess being Betty, but I don't think so.
Also Ice Queen pre-mushroom war( maybe pm) that be funny. To mark AT's time periods. PM for Pre-Mushroom War and AM-After Mushroom War. I lost the W , because it sounds cooler to just be AM and PM.
I thought Finn and Jake were out to get Santa, but it was just trying to stop the ice king
Just some fan art that I thought was funny.
BTW that bumper was totally fake, it was put in the show itself and will appear in it every time now.