Sneasel/Vulpix is not half bad. Acually, it's pretty good.
The rest are terrible though. As stated, you use devamped Buterfree wings, copyed and fliped it to both sides, and you just copy and pasted a Meowth on top. Not much of a mix to me...
Pikachu/Latias, not bad, but has horrible shading on the body and outlines. Fix please.
Angel Mew: Again, you copy and flipped the wings to both sides, and the shading is the same. Mew doesn't even have any shading at all, and it looks like you used default colors on Mew and the halo.
Keep practicing and you'll get better.