only thing I see wrong with it is you cropped it to high :) (joking)

re: "Oh, and I screwed up all the back muscle anatomy. Whatever...
And hands size. Well, this can happen...
And horns/head position.
And no head details.
And..."

Muscles are hard to get down. Personally I find leg muscles the hardest to draw. You've got the start of the trapezius In and on the neck. Also have what looks like the latissimus dorsi under and below like it should be. Depending on how buff this guy is, you could add some Serratus muscles.
Looks pretty good all in all though. My biggest problem with all muscles is figuring out how they stretch and bend x.x it kills me.

Heh, I know what's wrong, and I know how to draw it right. It's just that often I ignore my knowledge and draw things randomly :D

Lmfao xD same here. I applaud artists who spend that extra time and effort but sometimes I just don't have the patience. Same thing with perspective. I just eyeball it, while others might go so far as to set vanishing points and grid lines.

Nice :D

say what you will, but i for one look at this and think "this is just practice? i cant do this amazingly well even if i pour all my heart, soul and tears into a drawing!!"
Seriously dude, its beautiful, i love watching you cause of all the beautiful stuff you make
its not perfect, but its still wonderful and amazing, you got serious talent! and it can only get better from here on out!

I love watching you now cause of all of that, and i am excited to see where your talent and style will take you!

Just a practise. Seriously. I did the shading, I did the colors. And for a few hours I was experimenting with different blending modes, brightness, contrast, filters, to make it look both real and bright. There were other results, but I found them to be too unrealistic, that's why I got back to my previous shading style. At least I corrected my shading palette a bit.

So yes, it's not a drawing really. It's more like a practise :3

still, its really awesome~
i can only wish my practices could look this awesome xD
you have a real awesome talent good sir!

The essence of brute strength and the horns symbolize the masculinity. Nicely done!