Oooh! These are interesting! Wonder why no one's requesting from this!
I hope you don't mind but I'd love to give some constructive criticism on your pixels/artwork in general!
I really, really love the eyes! They just make the piece stand out oh, so much!
However they just don't match with the rest of the artwork,
if I were to explain this in artistic terms, I would say this:
it's flat coloured but the shaded eyes it a sort of unease but can work depending on how you balance out colours. (you kinda get what I mean here)
The lines seem quite too intensive for your character here, and although I'm not a big person on MS paint
I can see as to why you're using it??
I mean, started pixel art on MS paint as well for deviantART animated icons,
but I do know there's a command you can do to colour over certain colours.
But if you want the ease of not having to do that with a command,
there should also be more advanced programs that have either a "pencil tool"
or binary tool to be able to do pixel lines with multiple layers.
Like Firealpaca, krita and Paint Tool SAI.
Although I'd also say photoshop, that program is more for editing than drawing.
There should be an option called "preserve opacity" which allows you to colour over pre-existing lineart and a whole lot of other things!
Now with program stuff out of the way, I would also probably suggest to look at reference images to get a better sense on anatomy
Like with how legs/paws should look like, and the proportions of it.
I'd also suggest trying to practice a bit more on perspective, and shading combined
Try to work with angles, (this is something you do a lot in geometry when you draw 3D shapes).
Once you get used to drawing 3D shapes, try to incorporate them into your guidelines.
And you'll be able to do tons of views of characters.
light works in a similar fashion, and when used with perspective give so much more depth into your artwork
The tail looks pretty odd?? It looks like it's attached to the spine of the character or something Which is un-natural.
Tails would normally be by the butt-ox right on top. And try to make the nose a bit bigger, give it a snout to look more natural.
anyways, I hope my critique does help you in the future! As I see tons of potentail in your art!
-Your's truely, Blue.