"Adventure Time," which has been airing on Cartoon Network since 2010, is full of goofy characters, silly scenarios, and ridiculous humor. People often joke that those who make the show must be on drugs because there are so many odd moments-- usually a few in each episode. There are so many that I had to narrow it down to just 30, so comment if one of your favorites was left out!
1. When Marceline entered Finn’s memories and saw baby Finn doing this silly dance
It’s weird enough to have characters travel inside each other’s memories, but this little song and dance is one of the most memorable and weird "Adventure Time" moments. You can watch the whole thing here!
2. When Princess Bubblegum created a brother for the Earl of Lemongrab (because having one wasn’t weird enough).
The Earl of Lemongrab is extremely awkward, high strung, and uncomfortable for most to be around, yet he has a strong desire to rule others. Lemongrab blames PB for creating him without any ability to relate to others and complains about how lonely he is. Because of this, the Princess creates a second Lemongrab for him to live with. Of course they had to greet each other with poking and weird sounds.
3. When BMO showed Football how to be human
Football is BMO’s reflection. BMO imitates Finn for Football, who is amazed that BMO is so good at being a human.
4. When Mr. Pig and Tree Trunks got married
Despite Tree Trunks’ sweet and grandmother-like personality, she is actually a saucy little lady. She married Mr. Pig, who is equally cheeky, and the two are often seen committing awkward PDA.
5. When the Lemongrabs got in a fight over their doll, Lemonsweets
The Lemongrab twins are some of the strangest characters in general, and plenty of the weirdest "Adventure Time" moments involve them, but this is probably my favorite Lemongrab moment. The two fought over whether or not Lemonsweets should dance or go to sleep. Lots of screeching ensued.
6. When Jake turned into a car.
In this episode, the heroic duo take on the roles of detectives. Of course that requires Jake to turn into a police car and absorb Finn into the driver’s seat!
7. The fact that the Ice King writes gender-swapped fan fiction about Finn and Jake.
Fionna and Cake are one of the Ice King’s weird obsessions.
8. When the Lich was turned into the cutest (and strangest) baby.
The Lich is the main antagonist in "Adventure Time" but got turned into the innocent and adorable “Sweet P.” (which is short for Sweet Pig Trunks) when he was covered in the healing blood of a Citadel Guardian. This baby version of the Lich was then adopted by the equally cute and weird Mr. Pig and Tree Trunks.
9. When Finn and Jake had to convince a bunch of bears to stop partying inside a beast’s belly
Finn had to explain to the bears that they would be turned into “the stuff” if they didn’t leave the stomach they were partying in.
10. The fact that Peppermint Butler, as cute as he is, has close connections with the dark side of the supernatural world.
There are numerous episodes that suggest Peppermint Butler has connections with evil paranormal beings. For example, he is friends with Death and knows how to get in and out of the underworld. In another episode, he is seen summoning a demon within Cinnamonbun to communicate. He is also a huge fan of the infamously dangerous Vampire King.
11. When it was revealed that Marceline and the Ice King go way back.
When Marceline was just a little kid, she met Simon Petrikov, who later became the Ice King. When they met, Simon was a normal human being who worked as an archaeologist. The two survived the Mushroom War together and Simon took care of Marcy as if she was his own daughter. But somewhere along the way, Simon found a magical crown that provides its wearer with the power to create ice and snow. Eventually the crown took over his body and mind, resulting in his full transformation into the Ice King. He ended up having to abandon Marceline because he became extremely unstable and mad with power.
12. When Lumpy Space Princess lived with wolves
LSP left her parents in Lumpy Space to live independently in Ooo, but because she doesn’t have any income of her own, she was forced to survive in the woods. One day, she was found by wolves, who invited her to live with them. Eventually, she had to leave after becoming involved in a dramatic dispute between members of the pack.
13. When Finn had to “go dentist”
The concept of the dentist is very different in the post-apocalyptic world of Ooo. To go to the dentist, Finn is put in a well with snakes and butter to then be taken to an ant military base. There the ants promise to fix Finn’s teeth in exchange for helping them fight off their enemies.
14. Abracadaniel... just Abracadaniel...
What’s up with his body shape?
15. When it was revealed that Gunter the penguin is actually a very powerful space deity who was banished to live life in Ooo as a penguin.
Gunter is the Ice King’s favorite penguin, and is known for trolling him and others constantly. He is mischievous and loves to pull pranks with the help of his penguin friends. However, it is revealed in one of the later episodes that Gunter is actually a very dangerous space deity, named Orgalorg, who was cast down to Ooo to live life as a penguin. Gunter’s evil power within was hinted at in other episodes, like when Hunson Abadeer (Marceline’s biological father from the Nightosphere) refused to suck out his soul because he is “by far the most evil thing.”
16. When Football tried to take over BMO's life.
BMO “trades places” with Football (who's just a reflection...). Football then tries to steal BMO’s life outside of the mirror because it’s much more exciting. The two struggle until Football decides to move to the pond outside of their house instead.
17. When Finn wore Jake like a suit of armor
Finn took complete advantage of the “Jake suit.”
18. When the original Earl of Lemongrab became an evil dictator and ate his brother.
The OG Lemongrab is known for sentencing people to harsh punishments ("Seven years dungeon, no trial!"), screeching “UNACCEPTABLE,” and for his moto, “a lemon gives by taking.”
19. The "James Baxter the Horse" episode.
There’s an entire episode about a horse balancing on a beach ball….
20. When PB introduced Finn to her giant cat, Timmy.
Princess Bubblegum is a scientist who has created various lifeforms, including her over-sized kitty, Timmy, on whom she rides around.
21. When the Ice King tried to hit on Marceline (because he lost most of his memories)
As mentioned above, the Ice King and Marceline the Vampire Queen go way back, but the crown’s influence has caused him to lose most of his memories. Because of this (and his crippling loneliness), the Ice King tries flirting with Marceline, resulting in her working to help him remember their emotional past.
22. This…
‘Nough said.
23. When BMO was deleting files to get a rush
BMO ended up overdoing it and accidentally deleted some important files, which resulted in some damage that could only be repaired by BMO's original creator.
24. When Lumpy Space Princess developed a crush on Finn
LSP craves male attention and often misreads most responses to her advances.
25. The time that Ice King and his friends traveled to “big butt rock.”
This rock is supposed to be a “big butt,” which is already weird enough, yet it reminds me of a different body part...
26. When Finn helped a cat regain his throne in the Box Kingdom.
Finn and Jake are down to help anyone in need, including the Box Prince-- even if he is just an ordinary cat.
27. When Jake insisted on being a brick.
Jake wanted to experience what it was like to be a brick in a building that falls over.
28. When Finn tried to prevent the Lich from destroying the world by wishing the Lich never existed. 
In this alternate, Lichless-universe, Finn acquires the Ice King’s crown and goes crazy, destroying the world himself.
29. The “Food Chain” episode where food chains are explained in detail through Finn and Jake
The entirety of this episode depicts the circle of life. Finn and Jake become worms, plants, and birds all in a 12 minute time span.
30. When the Ice King spied on Finn and Jake from outside their house in a horse costume.
Finn and Jake were convinced that this horse had “poo brain,” but it ended up just being the Ice King in a costume.
