Arkeis: I really like it. I don't really have much to say on this sprite since what needs to be perfected has already been said by the others. The tail seems quite flat? Anyway, good job, it's currently in my shortlist.
Caelestis: It's a nice attempt, but there are certainly aspects of the sprite which need improving. The pose is a little awkward, I'm not sure where you were going with that. Parts of the line-art seem over-stretched, such as when the snake is turning its tail, and the lower segment of the "neck". I'd make your colours seem a little more vibrant than what you've got now. It's a little diluted at the moment. The shading falls flat (double meaning totally intended), and some areas need to look a little more three-dimensional (I'm not sure how you could go about doing this though). I also think the head is a little too small, and the tail curves off a little too soon, making it seem quite thin compared to the original artwork. The shiny version makes the snake look like it has a larger nostril, but eh, that's just how I see it ;P
Cartoons!: I like it! I see a few problems however; the curve with the body moving from left to right is a little too sudden and jagged, I really think it should be a lot smoother, so that the flow of the design is more apparent. Other than that, the colouring of the main body is a little too light; opt for a darker shde of brown to match the original artwork. The tip of the tail entering into the apple is barely visible, and at first I thought that the apple was hanging onto the tail rather than part of the tail. You might have tapered off the tail a little too much, as it looks weedy more than anything. Lineart near the tip of the tail needs small improvements, most noticeably where it curves, on the outer line. The fact that you've included one of the snake's yellow stripe patterns where the underbelly of the neck tapers off looks quite odd, as the pattern is barely visible in contrast to the pale underbelly. Also, aren't Gen 5 sprites meant to be facing left rather than right? As others have suggested, I'd flip the sprite. The spikes/thorns/whatever are a bit flat, most noticeably the last pair. As a positive, I think you've executed the devilish, sneaky and sinister grin of the snake perfectly, and it looks like you haven't had much trouble with the fangs, which I know a lot of people are struggling on.
DougJustDoug: It's certainly a refreshing pose in contrast to the rest of the sprites, I like how you've tried to differentiate yourself from the rest of the pack. The perspective is difficult to execute, yet you've seemed to pull it off. Colouring is great also. The lines are very smooth, but this could be attributed to how large the sprite is; I feel it still needs some downsizing. The thorns/spikes/I-don't-know-anymore, as with Cartoons!, seem quite flat and in this case very one-dimensional, and the pairs should also be more tightly bunched. Whilst having perfectly-shaped circles as the underbelly pattern and stripe pattern look neat, it makes the sprite seem.. I don't know, too processed? Too fake? It's hard to put into words, but I think it's the tiny imperfections and the irregular patterns which makes a sprite (of course, this is entirely subjective). Smaller nitpicks I have include making the head leaves seem a little less jagged and sorting out the fangs, as they look quite odd at the moment. Nevertheless, this sprite is definitely on my shortlist; I especially love the detailed eyes and the apple. It'll be interesting to see how you execute your back-sprite.
elcheeso: I've already said what I've needed to say about yours in #cap, but for the sake of everybody viewing this, I'll say it again (plus other things I've spotted). FIrst off, the sprite is very overwhelming and realistic(ish), no doubt due to the heavy shading. I think your artistic flair has come across a little too much in the sprite; spriting requires a different set of skills. The shading on the neck shouldn't be a straight, diagonal line, but rather a curve. The tail is quite thick, and I'm not seeing the logic by putting a line down the centre of the tip; you should remove it altogether. I can't see the fangs at all ;_;. The head leaves aren't in the right perspective, the one further away from us shouldn't be visible, and if so, only very slightly. The lineart in particular is very rough, especially on the tail, and there isn't a consistent thickness to the body of the snake. Other than all this, the colours you have chosen are fantastic and it is obvious that a lot of effort has been put into this sprite.
invalio: As others have pointed out, it's just a sprite-over, which requires a lot less skill than coming up with your own pose, and is more often than not frowned upon. The front sprite, because of this, is rather nice-looking, although quite underwhelming. It's the back sprite which has the most problems; the neck is too thin, and the tail is too tall. The other problems with the back sprite which I have have all been mentioned previously in the thread.
noobiess: I absolutely adore this sprite. The colouring is perfect, the shading, whilst simple, is executed brilliantly and you've managed to create the perfect expression for snakey. I have a few nitpicks however; as it stands, the neck of the snake (why do I keep on saying neck, the whole thing is a freakin' neck) looks quite flat and so does the tail. Other than that though, I see nothing wrong with it. It's certainly on my shortlist. Make sure when you're final submitting to change it to a transparent background! I don't know if having no fangs is intentional; I myself don't see a problem with it, but there would be a lot of users who would rather see the fangs.
Quanyails: I like the sprite, but as you know, I have a few problems with it. First of all (and I'm going to keep on saying this), the neck looks too fat and really should be slimmed down a little. The shading on the back sprite's neck might also be a little too contrasting, but I'm sure you can get away with it. The head leaves should be at a lower angle. Not a floppy, curved leaf but a leaf which is pointing at a lower angle. The face is still a little goofy :/ I don't really know how you could change that though. You've sprited the eyes so that the pattern on it now looks more like eyelids, which could contribute to why the sprite looks quite goofy. The colours you've chosen for the shiny sprite look good, and I love the contrast between the golden apple and the darker, more sinister body. It's interesting that you've chosen a gender change rather than a shiny change for the colouring of the apple; I know a lot of people are opposed to another gender difference, since near all CAPs have it, so it'll be interesting to see how that plays out (I myself have no problem with it).Still, this is definitely shortlist-worthy, on to my shortlist it goes!
Scorpio: The colours are certainly vibrant, maybe too much so? It's all very bright at the moment. I can't really see a definitive outline, I suggest making it all black. The underbelly (undertail?) of the tail has wayyy too many segments, I suggest taking a few out. The head leaves are rather short and could do with being stretched. Once again, the head area is in quite a state at the moment; you can't really make out the fangs, for instance. I await the shading o3o
Wyverii: My favourite sprite in the thread so far, hands down. Besides not making the curve at the tip of the tail so jagged, and changing the colour of the stripes to a yellow, to match the original artwork, I can't really fault your design in any way, you've done a fantastic job. I could see having less emphasis on the apple as a problem, but I'm not really bothered by it. I think that the shading of the neck in the backsprite, as with Quanyails' is a little too contrasted, but that's really just a minor nitpick.