Simon &amp; Marcy

"Simon &amp; Marcy" is the fourteenth episode of the fifth season of the American animated television series "Adventure Time". The episode was written and storyboarded by Cole Sanchez and Rebecca Sugar, from a story by Patrick McHale, Kent Osborne, and Pendleton Ward. 
It originally aired on Cartoon Network on March 25, 2013. It followed the re-run of "I Remember You".
In this episode, Marceline the Vampire Queen (voiced by Olivia Olson) reveals to Finn and Jake that 996 years before the events of the series, she and the Ice King (voiced by Tom Kenny)—then a human named Simon Petrikov—wandered the post-apocalyptic land after the destructive Mushroom War.
"Simon &amp; Marcy" was the last episode to feature Sugar as a storyboard artist. The episode received critical acclaim. Many loved its balance of humor and emotions, as well as its exploration of the Ice King's and Marceline's character.
The episode was viewed by 2.6 million viewers and received a 0.6 rating among adults between the ages of 18 and 49. The episode was later nominated for a Primetime Emmy Award for Short-format Animation at the 65th Primetime Emmy Awards.