Z-fighting occurs on chickens' feet from some angles when entity shadows are enabled
The Bug:
At certain angles, and heights, the feet of chicken have heavy Z-fighting. This bug is present older versions as well.

This behavior can also be seen in the video below:
How to Reproduce:
- Summon a Chicken with No AI, and look at its feet
- Rise above it a bit or to the side of it until at a specific angle. It will start to have heavy Z-fighting issue
- Also take note that below a certain distance the chickens feet are very light, and above a certain distance they are dark. This shows the Z-fighting is a threshold between these two points