{ Você podia dar uma olhada nos Zombies do Metal Slug e pegar umas idéias!
    http://www.metalslugsprites.net/enemies/zombies/
    Eu gostei dele andando (ou ao menos tentando andar).

Oh, now I see ^^
About the foot trail while he walks, well my other Zombie (http://pixeljoint.com/pixelart/35263.htm) does that, and I wanted to make this one different from that one =P

I'll try to make his clothes like a real cloth piece, but I never did this before (not sucessfully lol)

Thanks again, I'll see what I can do.

My english isn't the best either, I'm brazilian o,o'

For the standing animation, I would suggest just to make him breath.
The walking animation doesn't fit for a zombie, he should have difficulties to walk, maybe let one of his foot trail along on the floor ?

The size/rotate tool sin't a big problem, but as -I don't remember; sorry- said "to make a good animation, draw it more than once" (or something like that)

And just try to emulate textile texture on the cloth.

(sry for my english :/)

Thanks for your comment.
About the critics:
1- Yeah, now I see that the stand is horrible. I'm going to change it.
2- The walking animation was supposed to look "hard", with no articulations, like the classic zombies walked in old movies. If you think it is that bad, I think i'll do it again.
3- I used the Size/rotate tool for lots of animations, I like its effect. Is it really so bad?
4- About the shadings, well, what can I do to make it better?

Thanks man, I appreciate it ;D

You call this "stand" ? Anybody can do something like this dude ! And the same goes for the walkin animation. also those anim were made with size tool and rotation tool...
Shadings are basic.