King Harkinian is a character that appeared in the CD-i Zelda games, and later became a staple of Youtube Poop. Because of this, he commonly appears on Aeiou as well.
King Harkinian made a notable appearance in Robert Joe's Rant Adventures, where he had Dinner.
A far more extensive description of King Harkinian can be found here.
In the Or Something Like That threads, Harkinian is one of the top High Council members and a national leader, representing the YouTube portion of the Shellcorean-Lunarian-YouTube-New-Earth-Reich-Four alliance-nation. He also represents Hyrule. As a High Council member, King Harkinian has a personal military which is composed of the Hylian Royal Guard which when not at Hyrule Castle is housed in the King's personal battleship, the H.S.S. Harkinian Dynasty, which is powered by the Triforce and stored under Hyrule Castle when not in use.