I'm open for criticism so I can try to improve

Number one is really good, no issue there. The expression is very well done

Number two The horn seems a bit off center, but I could just be me. Other wise very clean with the lines which is great.

Number three looks pretty good, but again could just be me, but the horn looks off center.

Number four looks nice, the eyes are well done, but the shading on the upper body is off, maybe adding a bit more would help. Plus doing the paw holding the with three toes would help.

I hope this helped, :0
I know I'm always looking for constructive criticism