post your own work, or you will be banned. this is a warning, review the submission rules and in the future post only work that you have made by yourself.

Ello ello ello, what's all this then? Looks familiar

Well, practice is practice. I suppose a reference to my original would've been nice, but it's not technically a copy. Here's mine...
rjanes.co.uk/tutorials/pixelling_a_monster_sprite.php

I'll let the mods decide upon the fate of this entry. For critique though, I think you've tried to overdetail on your version. There's a lot of unnecessary dithering and in places like the little rock bit right at the top, some pillowshading, which never looks good. A good tip is when pieces are small, it's best to not even attempt pixelling in details and texture into skin. You seem to have tried this by the way of dithering and it doesn't work too well.

I dont copied, and I dont know the link of the image of reference.

Dude, you should probably mention somewhere that you've copied this?

 I believe I have seen this before... Reference?

 The colours you've used and the shading on the rings of the shell as especially good, great work for your first time! : )