Villain ideas

@ClownDicks  
I feel sheepish.

So, we at last got an Earth Pony villain everybody. Surprisingly, he was also the only villain to date to fully succeeded, scampering off with a huge bag of bits and apparently evading arrest.

@Trickquestion  
Because Equestria has no police, and the Royal Guards are all smug up in Canterlot being useless.

Sombra without any viewer age limits and executive meddling. Unleash this tyrannic walord who is hatred incarnate on a 18+ version of MLP and he will show you why he would be the best villain of the show.

@Trickquestion  
Something tells me it wasn’t enough to retire on like he wanted. Remember, he only wanted to sell it to the beautiful woman with the fake beard because he thought a certain Humanimal would be a no-show, not because she made a better offer.
 
He’ll be back.

One that talks to people like stereotypical 50’s father and is exceedingly polite. A magnificent bastard sort of guy.
 
Or a Doctor Octopus-like villain.

@Princess♠Molestia  
Like, “regular uses mechanical arms Doctor Octopus”, or “stole Spiderman’s body and is trying to be a superhero” Doctor Octopus?
 
Because honestly? Superior Twilight Sparkle sounds bucking amazing!

One or more of the minor antagonists turns into a major threat and sticks that way for a few episodes via magic, rigorous training, or augmentations.

@Trickquestion  
Mechanical arms. Mech arms octopus is best octopus.

@Trickquestion  
Yeah, but there’d need to be a lot of episodes devoted to it, his brief rise and long, drawn out fall, for that second one to be done justice.

One word…  
Tirek!  
 
But really, Tirek was a kick-ass villain in the original series. Creepy design, intimidating henchmen, and a suave and terrifying voice. Imagine how awesome he would be in generation 4. In fact, the first cartoon had some pretty awesome villains from what I understand. Tirek or Grogar returning would be phenomenal.

@Background Pony  
But they’re 2scary4little girls, so that’s never gonna happen.
 
That said, Jim Cummings for Hypothetical G4 Grogar and someone who can do a convincing impression of Mako for Hypothetical G4 Tirek.

@ClownDicks  
Interestingly enough, Victor Caroli, the original voice for Tirek, voices the Paralyzed Horse from Bravest Warriors. Since he is still doing voice work, they could just go ahead and have him voice Tirek again if they wished.

Some sort of Germ and germs.  

@Background Pony  
Did not know that. Figured he was either retired or dead.
 
Oh, and Tim Curry for Hypothetical G4 Smooze.

@ClownDicks  
It’s true, though I think Jeffrey Combs would make a great Tirek, utilizing a voice like his Scarecrow one. Jim Cummings as Grogar does sound amazing.

@Background Pony  
Especially if he’s going full SatAM Robotnik.
 
“Oh that’s good, that’s very good. Ohwaitwaitwait. Lower… lower… LOWER… Oh that’s just deliciousss!”

@Trickquestion  
This! I feel It would be really kind of jarring for a Crystal Pony to watch as one outsider is usurped only for another to take the throne. Now Cadance is no Sombra, but I think it would be great to show the crystal ponies as being very uneasy and cautious concerning outsiders. At the very least, it would lead to an interesting dilemma for Cadance and Shining and finally give some characters to some of those sparkly ponies of the north.

Some jerkish biker pony club who harass ponyville.

For a new Villain it would be best to look at the other ones and see what to use and not use. Nightmare Moon was an envious sister that wanted attention, Discord is the spirit of chaos and is “reformed”, Chrysalis is a parasite that attacked Canterlot out of a necessity and Sombra was a power mad Tyrant. So what qualities should be taken and what should be forgotten?

A T. rex in the Everfree Forest.

The Aquabats, due to an unfortunate-yet-hilarious misunderstanding.