The season was met with largely positive critical reception. In addition, several episodes and writers were nominated for awards; the episode "Thank You" was nominated for an Annie Award as well as an award at the Sundance Film Festival. "Too Young" was nominated for an Emmy Award. Storyboard artist Rebecca Sugar was also nominated for an Annie Award.
Finn and Jake must defend their home from the Cuties, a tiny race who believe themselves to be evil, destructive invaders.
The duo choose to partake in gladiatorial combat against the Fight King's ghost warriors, but Finn succumbs to bloodlust while Jake becomes obsessed in keeping a cool morale.
Finn and Jake enter Marceline's mind to awaken her from a sleep spell she had cast on herself, without knowing that they are being tricked by a person from her past.
The grounded Ice King hires a fire-manipulating hitman to attack Finn and Jake, without realizing the potentially deadly consequences.
The Earl of Lemongrab takes over the Candy Kingdom due to Princess Bubblegum's age regression, forcing her and Finn to try and get rid of him even if it means a life-altering decision.
The king and queen of Lumpy Space ask Finn and Jake to bring their daughter back home. At the same time, they attempt to stop a "monster" from destroying a village.
Finn and Jake are literally unable to move and are at the mercy of the Ice King.
Finn and Jake enter a competition for wizards in disguise so they can prevent Ice King from winning the grand prize: a kiss from Princess Bubblegum.
In this gender-swapped episode, Fionna and Cake must battle the evil Ice Queen.
Finn and his friends must come together as a genuine band in order to open the gate of the Door Lord and get back their taken items.
When Tree Trunks's apples go missing, she, Finn and Jake descend into the dark side of the Candy Kingdom in order to find the thief.
Finn and Jake receive an invitation to a masquerade dinner. It turns into a whodunit as guests start to meet their demise.
When another plague of Candy Zombies arises and Princess Bubblegum is among the undead, Finn and his friends are in a race against time to figure out how to stop it...without making things even worse!
Susan Strong asks Finn and Jake to help fight off the Glub Glubs in the sewers below to regain her people's home in Beautopia.
Finn awakens after an accident to find the Candy Kingdom citizens mysteriously gone and Jake acting crazier than usual.
Finn and Jake take on a request to protect Wildberry Princess from an unknown assassin. The assassin turns out to be a tiny cat assassin called Me-Mow, who ends up bribing Jake by poisoning him.
The Snow Golem visits the Fire Kingdom and finds an unlikely follower.
Jake dreams about his death, and Finn takes action when events from the dream start to come true.
Finn and Jake find the Ice King's video diary and have a chance to unearth his secrets.
The Ice King summons an army of snowmen to recover the secret tapes Finn and Jake are watching. They must work against the clock to find out the secrets enclosed within.
Finn and Jake play Cloud Hunt in Marceline's house, but they get trapped in her closet after she comes home.
Library books seek help from Finn and Jake to save them from the evil Moldari.
Cyclops tears may heal Finn and Jake's broken toes.
Finn and Jake play detective and try to solve Ghost Princess' murder.
Jake's dad presents a strange challenge to the guys when he appears to them in a holographic message, telling them about a dungeon he made for them.