This is a great model indeed, however I do agree with Lucas when he says the knee is too low, I know you want to express the idea of a towering gargantuan beast but, with a femur that long just doesnt work for your design, makes him looks unstable
Physically speaking, that femur would have to have a way larger diameter to be able to support that length.
I think the best way to convey that idea is to use some prop on him or another model in his base (assuming you are making one), that shows its true scale, ex: a church tower on his hand, a necklace of dead corpses, buildings remains little at his feet, im just spitballign here
You have a great model there and face is looking very good, congratulations my friend