Ice Armor is armor used by Ice King in "Thank You." The Ice King used it to safely stow himself away with sandwiches he stole from Finn and Jake. It is essentially useless in that the ice king is totally immobile while in it, leaving Finn and Jake to approach the obstacle however they can think to. They ultimately get Ice King out of the armor using axes.
Appearence
It is made of solid ice with a series of three spikes on top. It has blocky, immovable ice arms and a peephole through which Ice King sees, breathes, and mocks Finn and Jake. One of its hands is balled into a fist with a useless ice sword in it. Ice King trapped himself inside of it, appearing to have gone so far as to freeze all but his head solidly into it. Inside of the clear ice armor, Ice King wears nothing but his underwear.
Gallery
Ice King in Ice Armor
Breaking Ice Armor
Ice Armor Night Color
Finn and Jake breaking the Ice Armour