Humans

Humans are a critically endangered species in the post-apocalyptic setting of Adventure Time. Many characters marvel at Finn's humanity, like Princess Bubblegum in the episode "Susan Strong." Bob Rainicorn even says that he and his wife believed humans to be extinct. The very scarce human population in the Land of Ooo is likely due to the Mushroom War, which took place about a thousand years before the present story line.

There are other beings in Ooo (such as Phil and Old Man Henchman) who seem to resemble humans. However, Finn and the other characters do not recognize them as humans. According to the show's writers, these characters should be referred to as humanoids or mutants. It should also be noted that the last humans, Finn being the only confirmed example until "Betty" when Simon accidentally brings Betty into the future, look strikingly different from the alternate timeline's presumably unmutated humans, who have regular-sized eyes with visible whites and pupils, as well as more prominent noses. However, the humans in Pendleton Ward's other series, Bravest Warriors, also have little black eyes and no noses.

Known humans

 * Betty Grof
 * Finn
 * Fionna (fictional)

Deceased humans

 * Abraham Lincoln
 * Commander and Private (Animated Movie)
 * Marceline's mom (confirmed at Wondercon 2013)

Humans from the Farmworld timeline

 * Finn Mertens
 * Finn's mom
 * Finn's Dad
 * Finn's Baby Brother
 * Choose Bruce
 * Destiny Gang
 * Big Destiny
 * Trami
 * Tromo
 * Unnamed Destiny Gang Members

Known former humans

 * Simon Petrikov (now a wizard)
 * Moe (now a cyborg)
 * Randall N. Byron (now computer software; Comic only)
 * Business Men (now mutants)

Hybrid humans

 * Jay & Bonnie (Human/Pillow hybrid)
 * Stormo (by DNA)
 * Adventure Tim (Human/Dog hybrid; Comic only)
 * [little marcy] (Human/Demon)