Finn the Human, born Finn Mertens, is the main protagonist of the Cartoon Network series Adventure Time, portrayed by Jeremy Shada. A 17-year-old human raised in the post-apocalyptic world of Ooo by adoptive dog parents Joshua and Margaret, Finn is known for his bravery, strong moral compass, and relentless sense of justice. Initially a thrill-seeking boy who readily fought monsters and sought glory, his character evolved into a more introspective and mature hero over the series' run, grappling with complex themes of identity, loss, and responsibility. He wields a golden sword, possesses superhuman strength and durability, and is best friends with his adoptive brother Jake the Dog.

Princess Bubblegum, also known as Bonnibel Bubblegum or PB, is the intelligent and compassionate ruler of the Candy Kingdom in Adventure Time. A sentient humanoid construct made of pink gum and infused with human and candy DNA, she is the current incarnation of the Candy Elemental, granting her a deep connection to all candy and the ability to manipulate it. Though she appears in her late teens, she is over 800 years old, having emerged from a massive hive mind known as the Mother Gum after the Mushroom War.

Ice King, originally known as Simon Petrikov, is a central character in the Adventure Time franchise, evolving from a comical, inept villain into one of the show's most tragic and beloved figures. Once a kind-hearted human antiquarian, Simon was transformed into the Ice King after acquiring a magical crown that granted him cryokinetic powers but slowly drove him insane, altering his appearance with blue skin, a goblin-like nose, and a large white beard.