Still a bit hard to see, but looks better
You shouldn't use black outlines in the sprite itself (head/tail), only around it. What you can do instead is create a difference with light and dark colors next to eachother to create the line/transition effect.
I think you should change the position/shape of the body a bit aswell, you can take an other tibia animal as example like a lion or a horse to see how the perspective is done.
But good first monster