Well... kind of a mix. The king is real big, kinda why he's king. As for the others... well how about I just post a picture of your average giant. Feel free to say no I can easily come up with another kingdom.

Here is one of their Pyromancers


[hider=Average giant]
[img]http://img2.wikia.nocookie.net/__cb20140821142352/darksouls/images/e/e6/DS2_giant_concept.jpg[/img]
[/hider]

And they don't have a face like this one has, there's a hole where it's supposed to be. They are about 10 ft tall average, bulky as all hell as you can see though. Normal ones have the same build minus the cloak