I don't think that pencil sketches get anywhere near enough credit on DA. I LOVE this piece.
Clearly you have put a lot of time and effort into this drawing. You mention that you don't want to draw the other half of the face, but I think you would lose a lot of the impact of the piece if you did. It works brilliantly being long and thin.
I have marked you down slightly on the vision and originality of the piece, purely because you have drawn almost straight from a reference photo, not that this is a bad thing of course. Honestly, I think that that is the only thing I can mark you down on!
I note that it is not an exact copy, as you have added an ear and changed the focus. Also, you have managed to capture a wonderful sadness in the panthers eyes, which the original photo doesn't quite get, and your delicate pencil lines make the chin and neck look extra fluffy.
This is really good! I've seen little pencil drawings on dA, but I'd say! This one is fantastic! The fur is wondering, and very realistic. I love how you added whiskers to make it even more realistic. You must be an artist who usually does this. But guessing you had to look at another picture, I guess that's okay. It's hard to think at the top of your head. The eye is very detailed, and the whole photo is shaded quite well. I'd really like to see more art like this, and this is too good to even improve. I think that you have had alot of practice. Overall, this is beautiful!