Good color scheme, some good ideas in the limbs and torso. Always tough to do something new with arms and legs, but you seem to have done so, particularly with the shoulders.
The white triangle type pieces on the thighs should be turned around. The thigh in this kind of MOC should be rounded and its own unit, the curve of the triangle piece here messes up the overall outline of the thigh.
You have to be very careful how you put a head on shoulders, particularly in an animal-humanoid combiner MOC. It would probably be a lot more convincing if it was attached more Onua style, with the neck coming straight forward from the top of the shoulder. Look at how a real rhino and a real elk's shoulder-head arrangement is. That kind of tweak can help you tons, it's a silhouette thing.
Some cool stuff going on with the feet here. Kind of a high-heel shoe thing though, which you'd probably like to avoid if possible. Trying to integrate the heel more with the rest of the foot would help, and possibly making the color of those two segments the same so that they don't seem so separate. Color blocking can be used to visually merge pieces.
If you wanted to bring it more out of the classic Toa genre into a more unique animal-humanoid genre, you should heavily alter the anatomy. The neck-shoulder thing is part of that, but you can also do such things as gving him a second pair of knees, making the shoulders way wider than the hips, bending the torso into more of a semi-circle, and things like that.