Internal Enemies

[Ridge Troopa]

This one's got vast improvements over the last version, that's for sure.
The tiny bottom-most lock of hair on his back bothers me, it'd probably look better if you moved the lock above it up some and made the tiny part taller and longer.
The new body and legs are really great, so try to keep those how they are if you can. The front arm has two issues, one of which is still the shoulder armband; I would seriously consider making it bigger and move it down so you can see his shoulder (this is how it's supposed to be positioned - like I said before it looks stupid in BIS). The other is the fist, which right now looks like a ball instead of four digits. Fingers need to have more separation in terms of shape and the thumb just needs redoing.
His muzzle is turning into Paper Bowser's, which needs editing IMO. I think making it thinner/shorter and adding a tiny bit more definition between the front bulges and nose would help a lot.
The part of the jaw that connects to the cheek looks a little weird, it's got some kind of bulge on-level with his top teeth, which should be edited so it connects on an angle and not quite so smoothly.
The biggest spike looks all right, but the others need some reworking. In particular, you should move the top one up at least three or four pixels so the orange band is visible, and reshape everything else accordingly there so you can see some green too. The rim is great around the leg and biggest spike, but it should probably reach a bit higher behind his head. Also, I dunno if it's just me but the pure white part looks very strange right around that tiny spike near the top.
Last things are kind of nitpicks: see if you can't make the tail thicker and maybe add his other teeth.

Of course, the fact that I've got crit isn't to say I'd prefer your older one by any means. I'd be fine with seeing this one as-is over any previous version in MM; it's the best one and looks darn good.

EDIT: As far as my spriter senses go, eh, maybe a little... But I'll admit that I have topic replies set to immediate email notification...