Ice King

Ice King (real name: Simon Petrikov) is a major character conceived, but no longer acting as, the main antagonist of Adventure Time. His typical crime would be to kidnap a princess and force her to marry him, which Finn and Jake would foil every time. As his name suggests, Ice King is also his title, announcing himself as the King of Ice; the ruler of the Ice Kingdom.

Ice King assumes a role as one of the main protagonists to Adventure Time Insurrection, who journeys along side both Finn and Flame Princess in hope of rescuing Marceline and Jake, and ending the Electrogian war machine.

Powers
When Ice King is wearing his magic crown, it gives him the power to control all forms of ice and snow. This includes, but is not limited to, throwing solid bolts of lightning made of ice, moving ice with telekinesis, creating living manifestations of ice, turning water into ice, flash freezing his enemies, and the ability to onset a wintry weather on cue. In "Thank You," the Ice King makes a full armor of ice and says that it is "invincible." However, Finn and Jake eventually chopped away the ice. Also, in the episode "Princess Potluck," it is shown that he can sense when someone is tampering with the snow and/or ice around the Ice Kingdom. However, it is not known if he can use this ability with snow outside of the Ice Kingdom. His beard is apparently prehensile, operating much like a limb with partial shape-changing abilities, which he can wield in close combat. His beard also forms tiny wings that allow him to fly, although he must have both his beard and crown to fly. Because of his quick temper and arguably slow wit, he is unable to wield his powers as effectively as he should, but has proven himself capable of swiftly defeating Finn and Jake when amply provoked, as shown in "When Wedding Bells Thaw" and "The Eyes." In "Loyalty to the King" he spouts blue fire-like energy from his hands.

Ice King can also play the drums, once demonstrating a drum solo, and owns two drum sets, one of which is a green one with "#1 Babe" across the front. The set consists of a bass drum, a floor tom, a snare, a crash cymbal, a ride cymbal and a hi-hat. His other drum set, a red one, is in terrible shape, and smashed to pieces in a corner of his castle. He can also play the keyboard fairly decently. The fact that he has so many instruments lying around his castle indicates that he has a fair amount of musical ability. Also, in "Simon & Marcy," Simon shows that he sings songs to entertain Marcy, who says his songs are "so good." His drum sticks can also be seen in the side pocket of his backpack in any post-apocalyptic flashback.

Heat Resistant
He can support high heat temperatures, possibly due his low body temperature, as seen in "The Cooler," when he stayed in the Fire Kingdom without a heat suit or flame shield.

Fridjitzu Skills
In "The Chamber of Frozen Blades," the Ice King is shown to have studied the Ice Ninja art of Fridjitzu, and that his sanctum is filled with all sorts of ninja-esque weaponry and memorabilia.

Aside from his magic, Ice King owns a pair of nunchaku that he uses during the Wizard Battle to "cheat" as opposed to using his ice powers.

Wizard Eyes
Ice King also possesses a power known as "Wizard Eyes," which forces him to see certain things that normal people cannot. However, it also causes him to constantly see strange, nightmarish creatures. He notably used this power in "Mortal Recoil" when he witnessed the Lich take over the melted body of Princess Bubblegum. In "Mortal Recoil," as in the picture on the above-right, the camera briefly shows the viewer what the Ice King is seeing at the time. It gives the impression that the Ice King is imaginatively, completely insane. In the episode "Holly Jolly Secrets Part II," Simon Petrikov says that he saw strange visions while wearing the crown. In "Beyond this Earthly Realm," it is revealed that his Wizard Eyes allow him to see into the Spirit World, explaining that the freaky creatures surrounding him are spirits like Finn when he is transported to the Spirit World. In "The Empress Eyes", he seemed to possess an immunity to the Empress's hypnotic abilities.