Formerly Simon, this crowned villain of early Adventure Time lore rules a frozen realm.

This clue leads to Ice King. The sections below explain what it refers to, why it matches the clue, and why it may be appearing in the current trend cycle.

Simon Petrikov, more commonly called the Ice King, is a fictional character in the Adventure Time franchise. He was first introduced in the American animated television series Adventure Time. The character was the main antagonist of the show's early seasons and develops into a supporting character in later seasons. He is also a main character in the adult animated spin-off series Adventure Time: Fionna and Cake. The character is voiced by the American actor Tom Kenny in most appearances.

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The clue points to a crowned villain from early Adventure Time who was originally named Simon; that character is the Ice King.