one thing is the positioning is inconsistent, pushing him back and forward that much doesn't look so good, and also your attempt at animating the horns isn't an efficient one either, they just move, and not in synch with the body,
these are reasonably minor alterations, just making the positions more consistent frame to frame, adding an alternating 1 pixel down head bob on frames #1-#3, and quickly putting together a better approach to the horn animation, animate it in synch with his arm swing, because that would be the direction his body would swing/rotate.
also the forward animation has quite alot of head bob at the moment you want to make sure it is synchronized with your side on animation, before the edit, your side on had no head bob, so it clashed with the forward animation. also the arms and seemingly the legs too have much more extreme motions in your profile/side on view than they have in the downward one, you should try make them consistent with one another.
the overall design of the character is quite appealing.
the perspective matches your main character. but I'm not entirely sure about the colours. the colours on your main character look more subtle and desaturated, in this character they seem high contrast and vibrant in comparison, on their own both colour schemes look fine, but I'm not sure they mesh together perfectly