The first piece is very well done. The style reminds me a bit of the Matryoshka doll (russian dolls) when it comes to the big eyes and small nose & lips. I think it works and it definitely has it's own style. The choice of colors works real well, but the green background could have been a bit lighter. The dark green and the brown hair blend a bit (very earth-ie tones). I also like the texture on the octopus.
The bottom piece is painted well but the proportions are off on the figure (the head looks a bit too big & the right hip looks off, the leg just blends into where the hip should be. It could use a bit more definition). I would practice drawing some figures and look at some anatomy books/images if you are going to go for a more natural look.
I must say your proportions (8heads) is actually pretty accurate, but there is not as much attention for the important muscle groups.
The main trouble area's are at the crotch and the armpit, and the size of the head a little. I think alot of your problems can be solved by learning the important muscles
I would recommend you to get a few books on the subject because it's easier to learn from the start then dive straight into drawing from reality.
I would recommend Andrew Loomis Figure Drawing for all It's worth, and Michael Hampton's book