Z-fighting textures inside the frog's mouth

Summary:
When the frog opens its mouth to eat someone, Z-fighting of textures occur on the bottom of the frog's mouth.

Steps to reproduce:

1. Summon a frog.

2. Summon a mob that the frog can eat.

3. Watch the bottom of the frog's mouth.

Observed results:
The textures have Z-fighting inside the frog's mouth.

Expected results:
The frog's mouth textures should not have Z-fighting.

Video:

Image: