Ice King (formerly known as Simon Petrikov) is the main antagonist (often unintentionally) in the series. His typical misdeed is to capture princesses and marry them, which Finn and Jake always foil. He suggests to be called "King of Ice". He is the ruler of the Ice Kingdom.
Name: Ice King (formerly Simon Petrikov)
Family: Neptr (son), Jake (ex-wife), Princess Monster Wife (wife), Betty (former fiancée)
Ice King is normally portrayed as disagreeable, and short-tempered, but is more of a nuisance than an enemy and "isn't usually a serious threat," according to Princess Bubblegum. A genuinely tragic, lonely, and sympathetic character, Ice King spends most of his time kidnapping and imprisoning the various princesses of Land of Ooo, in hopes of someday marrying one. Due to his poor social skills, enduring short attention span and arrogant nature, Ice King is unable to woo any of his prisoners and often resorts to a forced marriage instead of the loving relationship he craves. However he can be a loving person as revealed in Princess Monster Wife. With no companions or friends aside from Gunter, his other penguin guards, and numerous ice creatures, Ice King expresses a continual zeal to spend time with anyone who will tolerate his company, especially his so-called "archenemies" Finn and Jake. In The Eyes, he takes on the disguise of a horse to spy on Finn and Jake in an effort to learn how to be happy, but fails that as well. He has been labeled a "sociopath" by the Cosmic Owl.
Ice King is a short, blue, elderly man with unusually pointy fingers, pointy toes, sharp teeth, and a goblin-like nose. He wears a dark blue tunic and has a large white beard that covers most of his body. Though the robe gives him the appearance of a larger man, Ice King's body is in fact exceptionally thin. Despite this, Ice King reveals that he is on a diet in What Have You Done? Ice King is rarely seen without his crown; without it he is powerless and he is revealed to have a short length of white hair atop his head. The only time he has been seen in shoes was when he was working out before Slime Princess came to talk to him in Loyalty to the King.