This. 
Prince Namor of Atlantis.
Darkseid of Apokolips.
Ofelia, aka Princess Moanna, Pan’s Labrynth.
Sir Humphrey Appleby. We all know he was really in charge. Not sure if I count as an American, though.
The king is a stick. Cousin Rudolf Rassendyll has all the moves.
Well we don’t actually see or hear him, but USSR Leader Dmitri in Dr. Strangelove seems pretty cool.
General Alcazar.
Kneel before Zod!
Winston Churchill. Yes, yes, I know. But there’s a mythical version of the man; and that is to whom I refer.
Rufus T. Firefly of Freedonia. His excellency’s car!
Moe Hailstone.
Queen Deidranna of Arulco.
Oops…I was conflating the two films! Sorry about that. Both The In-Laws and Bananas feature leaders of invented Central American countries who decree, um, interesting laws.
Wasn’t he also “Vigo the Butch”?
I don’t believe there is a difference between them.
The last man nearly ruined this place,
he didn’t know what to do with it.
If you think this country’s bad off now,
just wait 'til I get through with it.
Minister Kingsley Shacklebolt (Ministry of Magic)
Prince Ruprecht, as played by Steve Martin in Dirty Rotten Scoundrels: Ruprecht in Dirty Rotten Scoundrels - YouTube