First of all this picture looks really good! You really managed to make blood and gore come across perfectly.
To the appearance (positive):
The colors harmonize well together. It's really good that you didn't use bright colors. The matt colours symbolise decay and death. Nevertheless, you have set enough contrasts to be able to distinguish the individual body parts and the organs from each other.
I don't have many points of criticism, except that the legs of the wolf seem a bit too long to me. I know it's supposed to look bony, but it almost looks a bit too extreme. But in the end that's also a matter of taste.
Nevertheless, I have to say that this picture left a deep impression on me. The motive with the zombie animals isn't new anymore, but I'm glad that there are still artists who can draw something like this well.