Strolling through the Newgrounds as I complete a major project, and I stumbled on this image here.
Let me begin by saying how glad I am that this isn't a furry image of the sonic characters. There is a bit too much of that and it only hurts the image of the characters.
Anyway, I see what you were going for, but it's a little off. The pose in general is not too bad, but it is the crossed leg that bothers me. It looks like Shadow has 3 segments to his leg. Given that particular angle, I can see how it would have been difficult to draw.
Assuming that you just drew the lines and then colored them in, I recommend that you don't do that.
First draw out some roughs of the pose you are going for. Also, instead of drawing everything in a fluid line, break the body up into shapes, and make sure to layer them too.
For this particular image, when it came to the leg, I would first draw a rough shape of the thigh and then the calf ontop. This way you get a better sense of the foreshortening that is happening and you will be able to get a better image.
Once you have your rough lines and shapes drawn, make a new layer and lower the opacity of the rough lines.
Using your rough lines as a guide, draw in the clean lines.
There is a second major issue I see with this image. The chair's perspective is a little wonky.
The arm rests look like they are flat and have no volume.
I suggest you look at some examples of things drawn in perspective. You will get a better understanding of how everything works.
I know that this may be a little stressful to learn, but hang in there. Keep practicing and you will get better.