The finale to Adventure Time, the animated Cartoon Network television series created by Pendelton Ward and produced by Frederator Studios, happened in September 2018. Then in June 2020, Adventure Time: Distant Lands premiered. This is a four-part special focusing on Finn, Jake, BMO, Princess Bubblegum, Marceline, and Peppermint Butler.
The "BMO" episode, which came out in June 2020, followed BMO's adventure in space. The "Obsidian" episode, which came out in November 2020, explored Marceline and Princess Bubblegum's past, present, and future relationship. The "Together Again" episode, which comes out on May 20, 2021, sees Finn and Jake rediscovering their brotherly bond on an important quest.
10 The Snail Is Nowhere To Be Found
Every single episode of Adventure Time contains The Snail. This character is hidden somewhere in the scene, just waiting at the screen. But he does not appear in "BMO," the first episode of Adventure Time: Distant Lands.
This is the first time The Snail does not appear in canon throughout all of Adventure Time. That being said, his shell does appear in the background while BMO is in The Drift.
9 Moe And MO Co.
At the start of the "BMO" episode in Adventure Time: Distant Lands, he gets launched to Mars in a MO Co. rocket.
Well, MO Co. is that seemingly abandoned factory in the Bad Lands that viewers might recall from the Adventure Time episode "The More You Moe, The Moe You Know." It was founded by Moe, the old man who created BMO and the other MOs. In fact, in this episode are blueprints for a colony on Mars on his desk, which means Moe was always interested in Mars.
8 CGO's Backstory
In the "BMO" episode of Adventure Time: Distant Lands, the backstory of CGO is explored. The viewer finds out that a giant ball of electricity destroys part of the planet. This means another weapon of mass destruction was used besides the Mushroom Bomb during the Mushroom War.
Also, CGO mentions the gray aliens. These guys appeared in the Adventure Time episode "High Strangeness. The same exact ones!
7 Mr. M And Martien Mertens
BMO encounters a character named Mr. M in the "BMO" episode of Adventure Time: Distant Lands. He is a lot like Martin Mertens, Finn's father. They even have the same voice actor!
Both Mr. M and Martin Mertens have the "M" and are con artists. They both gamble and have the same body type. Both also have the same skin tone. On top of all this, Mr. M mentions children "always calling out their deadbeat parents," and he says at the end: "Here comes the rascal." Martien Mertens is the former and literally says the latter twice in Adventure Time.
6 BMO And The Tree Fort
At the end of the "BMO" episode in Adventure Time: Distant Lands, BMO crashlands into the ground right besides Finn and Jake's Tree Fort. However, the episode takes place before Adventure Time. So, Finn is still a child and Jake is just a teenager.
Moreover, it is revealed Finn and Jake lived in the treehouse for some time (several years actually) before Adventure Time begins.
5 The Rock T-Shirt
One of the biggest reveals of the "Obsidian" episode in Adventure Time: Distant Lands is how exactly and why precisely Princess Bubblegum and Marceline broke up before Adventure Time even began.
Well, in addition to this, the viewer witnesses a scene where Marceline plays a concert when she was young. At this show, Princess Bubblegum is in the front row and catches Marceline's t-shirt when she takes it off on stage. This is the same t-shirt (from "What Was Missing") Princess Bubblegum wears here and there in Adventure Time (and smells to remind her of Marceline).
4 Finn And Jake
Because the "Obsidian" episode of Adventure Time: Distant Lands takes place a few years after the ending of Adventure Time, Finn is now older. He was 17, although it is unknown how old exactly he is now. But he is taller, has facial hair, and even a tattoo.
The tattoo is Jake's face, surrounded by Forget-Me-Not flowers. Jake is not in this episode, and his fate is unclear at this point. However, the Forget-Me-Nots may be alluding to something.
3 Elise, Marceline's Mother
During the "Obsidian" episode of Adventure Time: Distant Lands, Marceline has a flashback.
This flashback reveals that her mother Elise survived the Mushroom War. Marceline and Elise lived in a trailer in the desert, which the viewers see in the "Everything Stays" episode of Adventure Time. Eventually, she does die, probably from radiation poisoning because Elise is seen coughing up blood and being quite sick.
2 "I Remember You"
"Remember You" is a song that Ice King and Marceline sing in the episode "I Remember You" in Adventure Time. It is about Ice King when he was Simon Petrikov, writing to Marceline in the past about how his mental health was deteriorating. The lyrics resemble these notes.
In the "Obsidian" episode of Adventure Time: Distant Lands, Simon Petrikov sings this tune again at an open mic in the Candy Kingdom (but gets interrupted by Glassboy).
1 Lady Rainicorn And Gunter
Lady Rainicorn, Jake's Rainicorn girlfriend, and Gunter, Ice King's pet, do not appear in the "Obsidian" episode of Adventure Time: Distant Lands.
However, Princess Bubblegum is seen wearing slippers that look like Lady Rainicorn. And, Simon Petrikov wears slippers too but they look like Gunter. (Where are Lady Rainicorn and Gunter?!)