I can't decide what I should do for the main villain of my Muppet Misadventures campaign. I have great plans for all of them, but I can't have too many world-ending antagonists in my kingdom. Basically, the four main ideas I have are:

Soul-Hungry Undead: A twisted amalgamation of rotting flesh, formerly a powerful necromancer. Driven mad by consuming so many souls, it has no agenda other than to consume all life in the world to feed its wretched mass.

Demon Lord: A towering fiend capable of leveling cities, they rule the Underworld with an iron fist and an adamantine arm-cannon. Cunning and strategic, they wish to corrupt the Material Plane and move in, since there's only so much real estate in heck.

War Machine: The machine itself is only an extension of the alien mass of tissue and nerves that pilots it. It still believes the world is in the midst of an ancient war, and seeks to destroy everything it deems an enemy.

Space-Rending Magician: Capable of bending space to their whim, they are in love with causing chaos across the world. They have meta-knowledge and don't want the party to 'win' since it means the 'audience' (players) won't want to see the 'show' anymore.

I like space-rending magician. Sounds a lot like Flowey or Jevil.

Alien Abberrent War Machine, Reapers ftw!

I’d rather start with character design, if you’ll permit.  Is the villain a muppet?  Because I think Sweetums could rule with an iron fist and Uncle Deadly would also be great. But he wouldn’t quite fit any of the choices.

If you are going to base it off the muppets, then do Jim Henson's Dark Crystal, its a D&D campaign as a movie.

From all the Options, I think you as the DM could have the most fun playing the reality bending Magician. 

I am thinking of things like Bill Cypher from Gravity Falls, or the Thanos Fight against the GotG where he used the reality Stone exclusively. That would also give you the option to use the BBEG throughout the Campaign, since he is pretty much invincible. He can turn the sword of the attacking Barbarian into a Rope, the Arrows of the Ranger into smoke or the Wizards Fireball into a swarm of Butterflies. 

The Campaign could be him spreading Chaos and the PCs are on a quest to find a way to weaken him enough to fight him. 

Quote from Portential >>

If you are going to base it off the muppets, then do Jim Henson's Dark Crystal, its a D&D campaign as a movie.

Yeah, now we're talking.  The skeksis are a great Big Bad.  Or if you want to be a huge nerd, Bowie in Labyrinth as the Space-Warping Magician.

Quote from Raoul97530 >>

From all the Options, I think you as the DM could have the most fun playing the reality bending Magician. 

I am thinking of things like Bill Cypher from Gravity Falls, or the Thanos Fight against the GotG where he used the reality Stone exclusively. That would also give you the option to use the BBEG throughout the Campaign, since he is pretty much invincible. He can turn the sword of the attacking Barbarian into a Rope, the Arrows of the Ranger into smoke or the Wizards Fireball into a swarm of Butterflies. 

The Campaign could be him spreading Chaos and the PCs are on a quest to find a way to weaken him enough to fight him. 

 Good ideas! I was thinking for their motives, and I like the idea of them being more theatrical about their appearances. They adopt the style of a stereotypical cartoon villain, using unnecessarily complex plans that seem to blow up in their face, and always 'getting away' in the end. However, if the party doesn't "go along with the act", then they drop the act and get serious with their schemes. It goes from theatrical schemes such as "steal a secret recipe and sell it for millions" to scary and harmful crimes like "open a dimensional rift to send an entire city into a plane of fire". Basically, they want the show to go on, and will do anything to ensure that.