Hot Diggity Doom and The Comet

Election day has come to the Candy Kingdom, but Princess Bubblegum (voiced by Hynden Walch) is distracted by the Catalyst Comet, a sentient comet that approaches Earth every 1,000 years. Her distraction with the comet causes her position as princess to be taken over by the King of Ooo (voiced by Andy Daly), a king made of earwax. This causes Princess Bubblegum and her second-in-command, Peppermint Butler, to retreat to an old cabin where Bubblegum used to spend her childhood days. (She later regains control over the kingdom in the Stakes miniseries.) Meanwhile, Gunter the penguin has just awakened his true form, a malevolent alien demon named Orgalorg in the events of a previous episode. Orgalorg uses one of Bubblegum's spaceships to blast off into space and absorb the comet's energy to gain its power and take over the universe.

Finn (voiced by Jeremy Shada) and Jake (voiced by John DiMaggio), the main protagonists of Adventure Time, blast off into space to stop Orgalorg. While wearing spacesuits, Finn and Jake go out to stop it but are separated. Finn goes inside of Orgalorg's large body, wherein his arm turns into a giant grass blade, which is one of his powers, and begins ripping the comet to shreds. After doing this he finds a strange circular-shaped being (voiced by Tig Notaro) living inside the comet. The being tells Finn that since he was a Catalyst Comet in a past life, he can have all the power he wants and ascend to a higher plain of being. Finn politely declines, saying he wants to stay on Earth. At that moment, Finn's deadbeat father Martin (voiced by Stephen Root) approaches them in the mouth of a giant space moth. He decides to take up on the comet's offer, and the both of them disappear. Finn and Jake are then rescued by Banana Man, and they return to Earth. A now critically injured Orgalorg falls down to Earth as well, turning back into the powerless Gunter.