King Nixel

King Nixel is the true main antagonist in the Mixels franchise''. ''He is a powerful tyrant and is ruler of the Nixels. King Nixel hates fun and creativity, and he wants to rid the world of it. He often sends Major Nixel to raid Mixels Land and steal all the Cubits so the Mixels can't fight back. King Nixel made no appearance at all in the first season of the show; his first appearance was in the special Mixel Moon Madness. At the end of the episode, Major Nixel is seen reporting Mixels on Mixel Moon to King Nixel, resulting in him shouting angrily. Major Nixel is very afraid of King Nixel. He later appears in the episode A Quest for the Lost Mixamajig as the main antagonist.

The Quest for the Lost Mixamajig
King Nixel was fully revealed in A Quest for the Lost Mixamajig. Fed up with Major Nixel's constant failures, King Nixel announces that he wants to take matters into his own hands. King Nixel's plan takes on a different and smarter strategy; rather than trying to steal the Mixels' Cubits, he wants to gather them up into one spot and then capture and destroy the Mixels. To do this, King Nixel creates a hoax involving a treasure called the "Mixamajig" that can only be found by "the chosen one." The chosen one being the Mixel who is given the magic key to the treasure. In reality, several Mixels were given a key, so when all the Mixels arrive at the spot the keys led them to, a portal between Mixels Land and Nixels Land, a free-for-all breaks out. While the Mixels are fighting, King Nixel sneaks up and traps them all in his airship.

However, once the Mixels realize the whole thing was a setup, they're quick to mix with each other, form an army of Maxes, and break out of the airship. But when King Nixel is challenged, he removes his cloak, revealing that his body is made entirely out of Nixels. A huge swarm of Nixels comes to their King's aid, climbing on his body and causing it to grow even larger. The Maxes realize that they can't beat King Nixel, so they decide to mix again. As this is basically mixing together every Mixel in existence, the result is an extremely powerful and colossal creature called the Ultra-Miximum Max. King Nixel and the Ultra-Miximum Max struggle for some time, but the Ultra-Miximum Max eventually gets the upper hand. The Ultra-Miximum Max manages to destroy the King's artificial body, and then smashes King Nixel's head, which turns out to be mechanized as well. As it turns out, King Nixel is actually about the same size as a normal Nixel. Once he's separated from his mechanical body, King Nixel runs away crying with the rest of his swarm, vowing revenge as he leaves.