This mecha paper model is Flame King, the former ruler of the Fire Kingdom and Flame Princess' father, based on the American animated television series Adventure Time, the papercraft is created by WebDude.
He first appears in "Incendium." Jake's mission was to impress him in order to convince him to let his daughter date Finn. After he thinks Finn kills Jake, he releases his daughter and promptly reveals that she is evil. He later appears in "Ignition Point," viewing a play which turns out to be Finn and Jake trying to warn him about an intended regicide.
After he demands that Finn and Jake be executed for apparently disguising "treason" as a play, Torcho and Furnius are discovered as the true conspirators, and they reveal that Flame King killed his own brother so that he could take the throne. In "Earth & Water," he was overthrown by his daughter and Cinnamon Bun and placed in the lantern where he once held his daughter. In "The Red Throne," the Flame Lord frees him in return for Flame Princess' hand in marriage. After Flame Princess refuses, however, Flame Lord and Flame King have a fistfight and end up imprisoned in the lantern together. [Source: wikia]
You can download the papercraft template here: Adventure Time - Flame King Free Papercraft Download