This is pretty amazing all round lol! So where to start, I really like the stretched out sort of surreal body, it definitely suits Venom. The colours are perfect and the shading on the purples is spot on.
The line shines are great they really bring him into the 3D world, especially on the six pack. Make him look much the strong!
The expression is very Venom lol, the teetch and tongue and whatnot are really well done. The symbol on his chest really suits the surface of his chest, I mean follows the bumps perfectly.
Overall, I cant say a bad word about it lol, which I guess you noticed heh.

Ah, Venom, one of the coolest comic Villains ever. Up there with... uhm... who? Spawn, you say? Ah, well, Spawn is so above any judgment that you can't confront him with any other villain but Venom is immediately after as a choice of villain.

Having said that (which had the only purpose of making you understand I am a fan of Venom), I must say that the first thing I noticed in this work was the lack of any liquid-like thread from his body (which is rarely as neat as we see it in this picture) and the absence of...huh... is it called froth? Such an expression from Venom as your picture has it (as if craving for something) really is missing that, I think, even more than some black thread of its liquid-like form, to make him look like Venom properly.
I've noticed you added some violet shading on his abdomen, but as you used it on the rest of the body to show a shade of lighting, it seems wrong placed there.
Another thing is about his overall "feeling". The pose, head bending and right hand seem to indicate a sort of craving, like I said, or make it seem like he's angry, ready to scream at the sky... the left hand fingers, though, are drawn in a way which makes it feel as if the position was different than the other hand's. It's weaker than the right hand, in my opinion.
I feel also that his colours are a bit too "bright", but that depends on which comics you read and which you prefer I guess.
A big pity is the lack of background/anything surrounding Venom. I like to imagine my big black evil guy, kneeling and screaming at the sky, above a pile of skulls or corpses, but I can't complain about that as I wouldn't be able to do it either.

Overall, you did a very good work with proportions, colouring and pose (apart from the left hand issue). I think that with only a bit of work it could come out definitely great, but this is already a more than good starting point.

Please remember, that this above is my personal opinion and you can freely disagree. I didn't meant to sound rude, though, so if it sounded like that I apologise.
Originality is lower because Venom is an abused subject of fanart, simply. And Impact is lower also, because it lacks a background.

=HtBlack