The King is a character that appears in the Sonic the Hedgehog television series. He is the father of Princess Sally and was the ruler of Mobotropolis and Mobius as a whole. Immediately following the end of the Great War, the King was dethroned by Dr. Robotnik and banished to the Void.
In the aftermath of the Great War, the king announced that he would hold a reception banquet and appoint Julian as the new Minister of Science. Not soon after, however, the King was overthrown by Julian, now having renamed himself Robotnik, who took over his kingdom in a coup. The king was then promptly captured by Robotnik and was thrown into the Void, a crystalline universe from which none could escape. Inside there, the King met Naugus, a dark wizard of great power and Robotnik's mentor, who wanted revenge against Robotnik for trapping him in the Void as well
In an alternate timeline created when Sonic and Sally used the Time Stones to travel back in time to stop Robotnik's coup before it could begin, the King met Sonic and Sally shortly after his meeting Julian, who both warned him of the events that would change everything, but it was too late. No sooner, Robotnik entered the palace, with his nephew Snively and army of Swat-bots, and announced his takeover. Like in the original timeline, the King was then captured and banished to the void.
Ten years after being imprisoned in the Void, Sonic the Hedgehog and his allies managed to enter the Void, finding the King alive and well. However, he only escaped the Void for a brief time with them before his body began to crystallize as a result of years of exposure to the Void's strange environment, which meant that he could no longer exist outside the Void. As a result, the King was forced to return there, much to the dismay of the Freedom Fighters and Sally in particular. Before he left, however, the King gave Sally a disk containing info on other ally Freedom Fighter groups.
- The King is not named during the series, but in the show's bible (and in the Archie Comics series based on that bible, not to be confused with the Sonic Bible), he is called King Acorn.
- The King makes a cameo in the first episode of Sonic Underground. A statue of him is shown in the middle of the city.
- The King's personal timeline in the series has some inconsistencies. He was imprisoned in the Void on the same day as Robotnik took over Mobotropolis, but he also later possesses a list of all Freedom Fighter groups, which did not exist when he was banished.
- The King's species is implied to be a squirrel, despite possessing the features that closely resemble that of a fox. According to Ben Hurst, the King is indeed intended to be a fox, but his species was addressed as a squirrel. His comic book counterpart was also addressed as a squirrel, before and after the Super Genesis Wave.